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authorJustin Gassner <justin.gassner@mailbox.org>2024-05-29 14:04:59 +0200
committerJustin Gassner <justin.gassner@mailbox.org>2024-05-29 14:04:59 +0200
commitc66c3bc73d5d627ec7051e9ada6316c98ae072e0 (patch)
tree21dc18f2773a50d7baac222bc5bad0cf7651395d
parentb9e2609169709f8aad257fa5e3a92cb780dfad3f (diff)
downloadmaster-c66c3bc73d5d627ec7051e9ada6316c98ae072e0.tar.zst
weiter
-rw-r--r--analytic2.tex10
-rw-r--r--bib/misc.bib2
-rw-r--r--bib/much.bib31
-rw-r--r--bib/test.bib4
-rw-r--r--convolution.tex63
-rw-r--r--fewstereveson.tex2
-rw-r--r--main.tex4
-rw-r--r--much.tex546
-rw-r--r--preamble.tex81
-rw-r--r--stresstensor.tex36
10 files changed, 686 insertions, 93 deletions
diff --git a/analytic2.tex b/analytic2.tex
index e0dc68f..13b6700 100644
--- a/analytic2.tex
+++ b/analytic2.tex
@@ -9,7 +9,7 @@
\begin{equation*}\tag{power-series-analytic-vector}
\sum_{n=0}^{\infty} \frac{A^n x}{n!} \, z^n
\end{equation*}
- has a nonzero radius of convergece.
+ has a nonzero radius of convergence.
If the power series converges for all $z \in \CC$,
we say that $x$ is an \emph{entire analytic vector} for $A$.
\end{definition}
@@ -66,13 +66,13 @@ This is a well-known consequence of the convergence behavior of power series.
\end{equation*}
for all $z,z'$ in the interior of $\gamma$.
The family of vectors $f(w) \in X$, indexed by complex numbers $w$ on the contour $\gamma$, can be viewed as a family of bounded linear functionals $C(f(w)) : X' \to \CC$
- via the canonical embedding $C : X \to X''$ of $X$ into its bidual. For every fixed $g \in X'$ the set of values $C(f(w))(g) = g(f(w))$ is bounded, because the function $g \circ f$ is continous and the contour is compact.
+ via the canonical embedding $C : X \to X''$ of $X$ into its bidual. For every fixed $g \in X'$ the set of values $C(f(w))(g) = g(f(w))$ is bounded, because the function $g \circ f$ is continuous and the contour is compact.
In other words, the family of functionals $C(f(w))$, $w \in \gamma$, is pointwise bounded.
The Uniform Boundedness Theorem implies that there exists a constant $M > 0$ such that $\abs{g(f(w))} \le M \norm{g}$ for all $w$ on $\gamma$ and all $g \in X'$.
\begin{equation*}
\abs*{g \parens*{\frac{Q(z) - Q(z')}{z - z'}}} \le \frac{M}{2 \pi} \norm{g} \int_{\gamma} \frac{dw}{\abs{w-z}\abs{w-z'}\abs{w-a}}
\end{equation*}
- If we restict $z,z'$ to a neighbourhood $N$ of $a$ that stays away from $\gamma$, then the integral on the right hand side is
+ If we restrict $z,z'$ to a neighborhood $N$ of $a$ that stays away from $\gamma$, then the integral on the right hand side is
bounded by a constant independent of $z$ and $z'$.
Absorbing all constants into $M' > 0$ we obtain
\begin{equation*}
@@ -121,9 +121,9 @@ This is a well-known consequence of the convergence behavior of power series.
\begin{equation*}
\sum_{n=0}^{\infty} \frac{\norm{A^n x}}{n!} t^n \le M \sum_{n=0}^{\infty} \frac{t^n}{r^n}
\end{equation*}
- is convergent for $t \le \lambda$ by majorization. Hernce $x$ is an analytic vector for the operator $A$.
+ is convergent for $t \le \lambda$ by majorization. Hence $x$ is an analytic vector for the operator $A$.
- Coversely, suppose that $x$ is analytic for the generator $A$ of $\sigma$.
+ Conversely, suppose that $x$ is analytic for the generator $A$ of $\sigma$.
Then, by \cref{definition:analytic-vector-operator}, $x$ lies in the domains of all powers $A^n$, $n \in \NN$, and the power series
\begin{equation*}
\sum_{n=0}^{\infty} \frac{\norm{A^n x}}{n!} z^n
diff --git a/bib/misc.bib b/bib/misc.bib
index b32be08..c5be6d3 100644
--- a/bib/misc.bib
+++ b/bib/misc.bib
@@ -19,7 +19,7 @@
title = {Time-Ordered Operator Products of Sharp-Time Quadratic Forms},
author = {Edward Nelson},
publisher = {Elsevier Science},
- journal = {Journal of Functional Analysis},
+ journaltitle = {Journal of Functional Analysis},
issn = {0022-1236,1096-0783},
date = {1972},
volume = {11},
diff --git a/bib/much.bib b/bib/much.bib
index c2f76f4..89287b3 100644
--- a/bib/much.bib
+++ b/bib/much.bib
@@ -27,3 +27,34 @@
edition = {1},
volume = {265},
}
+@book{Zhu1993,
+ title = {An Introduction to Operator Algebras},
+ author = {Kehe Zhu},
+ publisher = {CRC Press},
+ isbn = {0-8493-7875-3},
+ year = {1993},
+ series = {Studies in Advanced Mathematics},
+ edition = {},
+ volume = {},
+}
+@article{Uhlmann1961,
+ title = {Spectral Integral for the Representation of the Space-Time Translation Group in Relativistic Quantum Theory},
+ author = {Armin Uhlmann},
+ publisher = {Elsevier Science},
+ journal = {Annals of Physics},
+ issn = {0003-4916},
+ year = {1961},
+ volume = {13},
+ number = {3},
+ pages = {453--462},
+}
+@book{Streater1964,
+ title = {PCT, Spin and Statistics, and All That},
+ author = {Raymond F. Streater and Arthur S. Wightman},
+ publisher = {W. A. Benjamin},
+ isbn = {},
+ year = {1964},
+ series = {The Mathematical Physics Monograph Series},
+ edition = {},
+ volume = {},
+}
diff --git a/bib/test.bib b/bib/test.bib
index c6d07d6..f91a4ac 100644
--- a/bib/test.bib
+++ b/bib/test.bib
@@ -11,7 +11,7 @@
title = {The Evaluation of the Collision Matrix},
author = {G. C. Wick},
publisher = {American Physical Society},
- journal = {Physical Review},
+ journaltitle = {Physical Review},
issn = {0031-899X,1536-6065},
year = {1950},
volume = {80},
@@ -22,7 +22,7 @@
title = {Bounds on negative energy densities in flat spacetime},
author = {C. J .Fewster and S. P. Eveson},
publisher = {American Physical Society},
- journal = {Physical Review D},
+ journaltitle = {Physical Review D},
ISSN = {1089-4918},
year = {1998},
volume = {58},
diff --git a/convolution.tex b/convolution.tex
new file mode 100644
index 0000000..d3fb8bc
--- /dev/null
+++ b/convolution.tex
@@ -0,0 +1,63 @@
+\chapter{A Convolution Formula for Vector-Valued Tempered Distributions}
+\label{chapter:convolution}
+
+\blockcquote{Bisognano1975}{%
+ The extension to vector-valued tempered distributions is trivial.
+}
+Recall that the class $\schwartz{\RR^n}$ of complex-valued Schwartz functions on $\RR^n$
+is closed under convolution, a operation that assigns to functions $f$ and $g$ a third one, $f * g$,
+given by
+\begin{equation*}
+ (f*g)(x) = \int f(x-y) g(y) \, dy
+ \qquad x \in \RR^n.
+\end{equation*}
+
+\begin{definition}{Convolution of a Distribution with a Test Function}{}
+ Let $u \in \tempdistrib{\RR^n}$ be tempered distribution and
+ let $f \in \schwartz{\RR^n}$ be a Schwartz test function.
+ Then the \emph{convolution} of $u$ with $f$ is
+ the tempered distribution $u * f \in \tempdistrib{\RR^n}$ defined by
+ \begin{equation*}
+ (u * f)(g) \defequal u(\tilde{f} * g) \qquad g \in \schwartz{\RR^n},
+ \end{equation*}
+ where $\tilde{f}(x) = f(-x)$ for all $x \in \RR^n$.
+\end{definition}
+It is well-known that the convolution can be expressed by the integral
+\begin{equation*}
+ (u * f)(g) = \int u(\tau_x \tilde{f}@@) g(x) \, dx
+\end{equation*}
+emphasizing its character of a smoothing operation.
+The purpose of this appendix is to state and prove
+a vector-valued version of this formula.
+
+Let $X$ be a complex Banach space.
+Denote by $C^{\infty}(\RR^n,X)$ the vector space of all functions $f : \RR^n \to X$
+such that the derivatives $\partial^{\alpha} f$ exist and are continuous for all multi-indices $\alpha \in \NN^n$.
+We define the space $\schwartz{\RR^n,X}$ of \emph{$X$-valued Schwartz functions} to be the vector space
+\begin{equation*}
+ \schwartz{\RR^n,X} \defequal \braces{f \in C^{\infty}(\RR^n,X) \vcentcolon \norm{f}_{\alpha,\beta} < \infty \forall \alpha,\beta \in \NN^n}
+\end{equation*}
+equipped with the locally convex topology induced by the family of seminorms
+\begin{equation*}
+ \norm{f}_{\alpha,\beta} = \sup_{x \in \RR^n} \abs{x^{\alpha}} \norm{\partial^{\beta} f(x)}_X.
+\end{equation*}
+We define the space $\tempdistrib{\RR^n,X}$ of \emph{$X$-valued tempered distributions} to be the vector space
+\begin{equation*}
+ \tempdistrib{\RR^n,X} \defequal \BoundedLinearOperators[\big]{\schwartz{\RR^n},X}.
+\end{equation*}
+equipped with the bounded convergence topology.
+
+\begin{proposition}{Vector-Valued Convolution Formula}{}
+ Let $v \in \tempdistrib{\RR^n,X}$ be tempered distribution with values in a Banach space $X$, and
+ let $f \in \schwartz{\RR^n}$ be a Schwartz test function. Then one has
+ \begin{equation*}
+ (v * f)(g) = \int v(\tau_x \tilde{f}@@) g(x) \, dx \qquad g \in \schwartz{\RR^n}.
+ \end{equation*}
+\end{proposition}
+
+Der Beweis ist in Arbeit ;)
+
+%\nomenclature[B]{$\BoundedLinearOperators{X,Y}$}{bounded linear operators from $X$ to $Y$\nomnorefpage}
+
+\chapterbib
+\cleardoublepage
diff --git a/fewstereveson.tex b/fewstereveson.tex
index fdda174..cb1918b 100644
--- a/fewstereveson.tex
+++ b/fewstereveson.tex
@@ -3,7 +3,7 @@
\section{Test}
-Goal: make \cite{Fewster1998} rigorous based on the previous chapter
+Goal: make~\cite{Fewster1998} rigorous based on the previous chapter
\chapterbib
\cleardoublepage
diff --git a/main.tex b/main.tex
index 91aaaab..9158399 100644
--- a/main.tex
+++ b/main.tex
@@ -1,5 +1,6 @@
\input{preamble}
-\includeonly{stresstensor,fewstereveson,much,commutatortheorem,analytic2,symbols,index}
+\input{ushyphex}
+\includeonly{stresstensor,fewstereveson,much,commutatortheorem,convolution,analytic2,symbols,index}
\begin{document}
\frontmatter
\include{titlepage}
@@ -17,6 +18,7 @@
\appendix
\include{sampleappendix}
\include{commutatortheorem}
+\include{convolution}
\include{analytic2}
\backmatter
\include{bibliography}
diff --git a/much.tex b/much.tex
index 58aeab3..a7f9bbf 100644
--- a/much.tex
+++ b/much.tex
@@ -1,23 +1,22 @@
-\chapter{A quantum energy inequality involving local modular data}
-
+\chapter{A Quantum Energy Inequality Involving Local Modular Data}
\cite{Much2022}
\begin{equation*}
\innerp{\psi}{\energydensity(f)\psi} \ge
- - \epsilon - \norm{\smash[b]{\Delta}_{\smash[t]{\sharp}}^{-1/2} \ft{g}_{\lambda}(K_{\raisebox{5pt}{\footnotesize$\sharp$}}) \energydensity(f) \fockvaccum}
+ - \epsilon - \norm{\smash[b]{\Delta}_{\smash[t]{\sharp}}^{-1/2} \ft{g}_{\lambda}(K_{\raisebox{5pt}{\footnotesize$\sharp$}}) \energydensity(f) \FockVacuum}
\end{equation*}
-
\section{Misc}
-\todo{Put this somwhere else.}
+\todo{Put this somewhere else.}
A \emph{Lorentz transform} is a linear automorphism of Minkowski spacetime
which preserves the Lorentz bilinear form.
Lorentz transforms are usually represented by (real) $4 \times 4$ matrices,
with respect to the standard basis.
-the \emph{Lorentz group} $\FullLorentzGroup$.
+
+The \emph{Lorentz group} $\FullLorentzGroup$.
\begin{equation*}
\FullPoincareGroup = \RR^4 \ltimes \FullLorentzGroup
\end{equation*}
@@ -44,7 +43,7 @@ Poincaré covariance
\begin{definition}{Von Neumann Algebra of Local Observables}{}
\begin{equation*}
- \localalg{\spacetimeregion{O}} = \braces{b(\varphi(f)) \mid b, f \in \realschwartz{M}, \supp f \subset \spacetimeregion{O}}''
+ \localalg{\spacetimeregion{O}} = \braces{b(\varphi(f)) \mid \text{$b$ bounded}, f \in \realschwartz{M}, \supp f \subset \spacetimeregion{O}}''
\end{equation*}
\end{definition}
@@ -52,10 +51,10 @@ Poincaré covariance
\index{modular!theory}
If $\hilb{H}$ is a Hilbert space
-we shall denote the $C^*$-algebra of all bounded linear operators on $\hilb{H}$ by $B(\hilb{H})$.
+we shall denote the $C^*$-algebra of all bounded linear operators on $\hilb{H}$ by $\BoundedLinearOperators{\hilb{H}}$.
\begin{definition}{Cyclic and Separating Vectors}{}
- Suppose $\hilb{H}$ is a Hilbert space and $\mathcal{A}$ is a $C^*$-subalgebra of $B(\hilb{H})$.
+ Suppose $\hilb{H}$ is a Hilbert space and $\mathcal{A}$ is a $C^*$-subalgebra of $\BoundedLinearOperators{\hilb{H}}$.
A vector $\Omega \in \hilb{H}$ is called
\begin{itemize}
\item \emph{cyclic}\index{cyclic vector} for $\mathcal{A}$ if the vector set $\mathcal{A} \Omega$ is dense in $\hilb{H}$.
@@ -66,19 +65,37 @@ Occasionally, a vector that is both cyclic and separating is called \emph{standa
Recall that the commutant of a set $\mathcal{S} \subset B(\hilb{H})$ of operators
is defined as the set of all operators $T \in B(\hilb{H})$ which commute with all operators $S$ in $\mathcal{S}$.
-We shall denote the commutant of $\mathcal{S}$ by $\mathcal{S}'$.\nomenclature{$\mathcal{A}'$}{commutant of $\mathcal{A}$}
+We shall denote the commutant of $\mathcal{S}$ by $\mathcal{S}'$.\nomenclature[A]{$\mathcal{A}'$}{commutant of $\mathcal{A}$}
\begin{proposition}{}{cyclic-separating}
- \begin{enumerate}[label=(\roman*),nosep,leftmargin=*,widest=ii]
- \item A vector is cyclic for $\mathcal{A}$ if and only if it is separating for $\mathcal{A}'$.
- \item If $\vNa{M}$ is a von Neumann algebra, then a vector is cyclic and separating for $\vNa{M}$
- if and only if it is cyclic and separating for $\vNa{M}'$.
+ Let $\hilb{H}$ be a Hilbert space and $\mathcal{A}$ be a $C^*$-subalgebra of $\BoundedLinearOperators{\hilb{H}}$.
+ \begin{enumerate}
+ \item \label{item:first} A vector is cyclic for $\mathcal{A}$ if and only if it is separating for $\mathcal{A}'$.
+ \item \label{item:second} If $\mathcal{A}$ is a von Neumann algebra, then a vector is cyclic and separating for $\mathcal{A}$
+ if and only if it is cyclic and separating for $\mathcal{A}'$.
\end{enumerate}
\end{proposition}
\begin{proof}
- \todo{xxx}
- The second assertion directly follows from the first and the fact that $\vNa{M}'' = \vNa{M}$.
+ First, suppose that $\Omega \in \hilb{H}$ is cyclic for $\mathcal{A}$.
+ If $A'$ is an element of $\mathcal{A}'$ with $A' \Omega = 0$,
+ then $A' A \Omega = A A' \Omega = 0$ for all $A \in \mathcal{A}$.
+ This means that $A'$ vanishes on the dense subspace $\mathcal{A} \Omega$,
+ and thus on all of $\hilb{H}$, i.e.\ $A'=0$.
+ This proves that $\Omega$ is separating for $\mathcal{A}'$.
+
+ Conversely, suppose that $\Omega$ is separating for $\mathcal{A}'$.
+ We have to show that the closed subspace $\overline{\mathcal{A}\Omega}$ is all of $\hilb{H}$.
+ Let $P$ be the orthogonal projection onto $\overline{\mathcal{A}\Omega}$.
+ Clearly, any element $A$ of $\mathcal{A}$ maps $\overline{\mathcal{A}\Omega}$ into itself.
+ Thus, $PAP=AP$, and the same holds for $A^*$, that is, $PA^*P=A^*P$.
+ Taking the adjoint of the second equation, we get $PAP=PA$. Hence, $P \in \mathcal{A}'$.
+ Now, $P \Omega = \Omega = I \Omega$, where $I$ is the identity operator on $\hilb{H}$ which obviously also belongs to $\mathcal{A}'$,
+ and the assumption that $\Omega$ is separating for $\mathcal{A'}$ implies $P=I$.
+ Consequently, $\overline{\mathcal{A} \Omega} = \hilb{H}$.
+
+ Statement~\ref{item:second} directly follows from~\ref{item:first} and
+ the fact that $\mathcal{A}'' = \mathcal{A}$ by the Double Commutant Theorem.
\end{proof}
If $\Omega$ is separating for $\mathcal{A}$,
@@ -87,7 +104,7 @@ with a unique $A \in \mathcal{A}$.
This allows us to define an (anti-linear) operator $S_0$ in $\hilb{H}$ with domain $\mathcal{A}\Omega$ by
\begin{equation}
\label{equation:definition-s0}
- \quad S_0 A\Omega \defequal S_0 A^*\Omega \qquad A \in \mathcal{A}.
+ \quad S_0 A\Omega \defequal A^*\Omega \qquad A \in \mathcal{A}.
\end{equation}
The operator $S_0$ is densely defined if and only if $\Omega$ is cyclic for $\mathcal{A}$.
Since the $*$-operation on $\mathcal{A}$ is involutive,
@@ -100,12 +117,12 @@ the range of $S_0$ coincides with its domain.
\begin{proof}
By \cref{proposition:cyclic-separating},
$\Omega$ is also cyclic and separating for the commutant $\vNa{A}'$.
- Hence we may, analogously to $S_0$,
+ Hence we may, in analogy to $S_0$,
define another anti-linear operator $F_0$ in $\hilb{H}$ with dense domain $\mathcal{A}' \Omega$ by
\begin{equation*}
- \quad F_0 B\Omega \defequal F_0 B^*\Omega \qquad B \in \mathcal{A'}.
+ \quad F_0 B\Omega \defequal B^*\Omega \qquad B \in \mathcal{A'}.
\end{equation*}
- By definition of $S_0$ and $F_0$ we have for every $A \in \mathcal{A}$ and $B \in \mathcal{A}'$
+ By definitions of $S_0$ and $F_0$, we have for every $A \in \mathcal{A}$ and $B \in \mathcal{A}'$
\begin{equation*}
\innerp{S_0 A \Omega}{B \Omega} =
\innerp{\Omega}{AB \Omega} =
@@ -124,10 +141,10 @@ the range of $S_0$ coincides with its domain.
Suppose $\Omega$ is a cyclic and separating vector for a von Neumann algebra $\mathcal{A}$.
The closure $S = \operatorclosure{S_0}$
of the operator $S_0$ defined on $\mathcal{A}\Omega$ by
- $S_0 A\Omega = S_0 A^*\Omega$
+ $S_0 A\Omega = A^*\Omega$
for $A \in \mathcal{A}$
is called the
- \emph{Tomita operator}\index{Tomita operator}\index{operator!Tomita}\nomenclature{$S$}{Tomita operator}
+ \emph{Tomita operator}\index{Tomita operator}\index{operator!Tomita}\nomenclature[S]{$S$}{Tomita operator}
for the pair $(\mathcal{A},\Omega)$.
\end{definition}
@@ -135,7 +152,7 @@ It is a well-known fact that closed operators can be decomposed
in a similar fashion to the polar coordinate representation $z = e^{i\arg z} \abs{z}$
of a complex number.
We state the theorem in its somewhat uncommon variant for anti-linear operators,
-as this is our only use case.
+as this will be our only use case.
\begin{theorem}{Polar Decomposition for Anti-Linear Closed Operators}{polar-decomposition}
\index{polar decomposition}
@@ -156,7 +173,7 @@ as this is our only use case.
\end{theorem}
Proofs of this statement are contained in~\cite{ReedSimon1} and~\cite{Schmüdgen2012}.
-When we speak of \emph{the} polar composition we tacitly assume that the additional conditions
+When we speak of \emph{the} polar composition of an operator we tacitly assume that the additional conditions
ensuring uniqueness are satisfied.
Now we are able to introduce the fundamental objects of modular theory.
@@ -170,7 +187,7 @@ Now we are able to introduce the fundamental objects of modular theory.
\end{equation*}
be its polar decomposition.
The anti-unitary operator $J$ is called
- \emph{modular conjugation}\index{modular!conjugation}\nomenclature{$J$}{modular conjugation}.
+ \emph{modular conjugation}\index{modular!conjugation}\nomenclature[J]{$J$}{modular conjugation}.
The positive selfadjoint operator $\Delta$ is called
\emph{modular operator}\index{modular!operator}\index{operator!modular}\nomenclature{$\Delta$}{modular operator}.
The pair $(J,\Delta)$ is said to be the \emph{modular data}\index{modular!data}\index{modular!objects} associated to
@@ -187,8 +204,6 @@ Now we are able to introduce the fundamental objects of modular theory.
The modular group is a strongly continuous one-parameter unitary group on $\hilb{H}$.
-\newpage
-
\begin{proposition}{}{modular-data-unitary}
Suppose $\vNa{M}$ is a von Neumann algebra acting on a Hilbert space $\hilb{H}$.
Let $U$ be a unitary operator on $\hilb{H}$.
@@ -202,11 +217,11 @@ The modular group is a strongly continuous one-parameter unitary group on $\hilb
\begin{proof}
To prove the first assertion,
consider any $A \in (U\vNa{M}U^*)''$.
- By the double commutant theorem,
+ By the Double Commutant Theorem~\cite[Theorem 18.6]{Zhu1993},
it suffices to show that $A \in U\vNa{M}U^*$.
As $\vNa{M}$ is a von Neumann algebra,
this is equivalent to $U^*\! AU \in \vNa{M}''$,
- again by the double commutant theorem.
+ again by the Double Commutant Theorem.
Let $B \in \vNa{M}'$.
It is easy to check that $UBU^* \in (U\vNa{M}U^*)'$.
By assumption, $A$ lies in the commutant of $(U\vNa{M}U^*)'$.
@@ -221,15 +236,15 @@ The modular group is a strongly continuous one-parameter unitary group on $\hilb
Now $A=0$ follows from the assumption that $\Omega$ is separating for $\vNa{M}$.
We have shown that the mapping $UAU^*U\Omega = UA\Omega$ from $U\vNa{M}U^* \to \hilb{H}$ is injective.
- Let $S = \overline{S_0}$ be the Tomita operator associated to $(\vNa{M},\Omega)$,
- and let $S' = \overline{S'_0}$ be the Tomita operator associated to $(U\vNa{M}U^*,U\Omega)$.
+ Let $S = \operatorclosure{S_0}$ be the Tomita operator associated to $(\vNa{M},\Omega)$,
+ and let $S' = \operatorclosure{S'_0}$ be the Tomita operator associated to $(U\vNa{M}U^*,U\Omega)$.
Then we have
\begin{equation*}
(S'_0 U) A \Omega =
S'_0 (U A U^*) U \Omega =
(U A^* U^*) U \Omega =
U A^* \Omega =
- U S_0 A \Omega
+ (U S_0) A \Omega
\end{equation*}
for all $A \in \vNa{M}$. Consequently, $S'_0 = U S_0 U^*$ as operators with domain $U\vNa{M}\Omega$.
Taking the closure, we obtain $S' = U S U^*$.
@@ -243,12 +258,12 @@ The modular group is a strongly continuous one-parameter unitary group on $\hilb
associated to the pair $(U\vNa{M}U^*,U\Omega)$.
\end{proof}
-\newpage
-
Finally, let us outline how modular theory enters into algebraic quantum field theory.
-\begin{theorem}{Reeh-Schlieder Theorem}{reeh-schlieder}
- \todo{spell it out}
+\begin{theorem}{Reeh--Schlieder Theorem}{reeh-schlieder}
+ Let $\spacetimeregion{O}$ be any open spacetime region.
+ Then the vacuum vector $\Omega$ is cyclic for $\localalg{\spacetimeregion{O}}$.
+ If $\spacetimeregion{O}'$ is non-empty, then $\Omega$ is also separating for $\localalg{\spacetimeregion{O}}$.
\end{theorem}
By Reeh-Schlieder (\cref{theorem:reeh-schlieder}), the vacuum $\Omega$ is cyclic and separating for $\localalg{\spacetimeregion{O}}$.
@@ -286,7 +301,7 @@ since they are transformed into each other by space inversion.
\end{proof}
In the standard representation of the Lorentz group, the boost (or velocity transformation) along the $x^1$-axis
-with rapidity $2 \pi t$ is given by the matrix\footnote{
+with rapidity $2 \pi t$ is given by the matrix\footnote{%
This matrix depends on the choice of metric signature.
Ours is $(+,-,-,-)$.
For $(-,+,+,+)$, use
@@ -300,21 +315,22 @@ with rapidity $2 \pi t$ is given by the matrix\footnote{
\end{equation*}
}
-\begin{equation*}
+\begin{equation}
+ \label{equation:lorentz-boost}
\Lambda(t) = \begin{pmatrix}
\cosh(2 \pi @ t) & \sinh(2 \pi @ t) & \; 0 \; & \; 0 \; \\
\sinh(2 \pi @ t) & \cosh(2 \pi @ t) & 0 & 0 \\
0 & 0 & 1 & 0 \\
0 & 0 & 0 & 1 \\
\end{pmatrix}
-\end{equation*}
+\end{equation}
The following proposition shows that $t \mapsto \Lambda(t)$ is
a one-parameter subgroup of the stabilizer group of the right wedge
with respect to the action of the Lorentz group on subsets of Minkowski space.
\begin{proposition}{}{}
- \begin{enumerate}[label=(\roman*),nosep,leftmargin=*,widest=ii]
+ \begin{enumerate}
\item $\Lambda(s + t) = \Lambda(s) \Lambda(t)$ for all $s,t \in \RR$.
\item $\Lambda(t) \rightwedge = \rightwedge$ for all $t \in \RR$.
\end{enumerate}
@@ -349,7 +365,9 @@ with respect to the action of the Lorentz group on subsets of Minkowski space.
and~\eqref{equation:image-right-wedge}. Now it follows from $\Lambda(-t) = \Lambda(t)^{-1}$ that in fact $\Lambda(t) x = y$.
\end{proof}
-\begin{theorem}{Bisognano-Wichmann Theorem \textmd{\cite{Bisognano1975}}}{}
+It can easily be seen that $\rightwedge' = \leftwedge$, and so \cref{theorem:reeh-schlieder} applies.
+
+\begin{theorem}{Bisognano--Wichmann Theorem \textmd{\cite{Bisognano1975}}}{bisognano-wichmann}
For the theory of a free scalar field in Minkowski spacetime,
let $\spacetimeregion{O} \mapsto \localalg{\spacetimeregion{O}}$ be the net of von Neumann algebras of local observables.
If $(J,\Delta)$ is the modular data associated to the algebra $\localalg{\rightwedge}$ of the right wedge and the vacuum $\Omega$, then
@@ -400,7 +418,7 @@ That this is generally true is the statement of the following Lemma.
for all Borel functions $f : \RR \to \CC$.
\end{lemma}
-\question{Ist diese Aussage korrekt? Ist mein Beweis richtig? Geht der auch einfacher?}
+\todo{write down the simpler proof}
\begin{proof}
For each regular value $\lambda \in \rho(A)$ let
@@ -453,14 +471,14 @@ That this is generally true is the statement of the following Lemma.
\end{equation*}
-Recall that Stones Theorem \todo{add reference} states that
+Recall that Stone's Theorem \todo{add reference} states that
every strongly continuous one-parameter unitary group
is of the form $t \mapsto e^{itK}$ with a uniquely determined
selfadjoint operator $K$, which is called \emph{infinitesimal generator} of the group.
\begin{definition}{Modular Hamiltonian}{}
The infinitesimal generator of the modular group associated to a spacetime region $\spacetimeregion{O}$ is called the
- \emph{modular Hamiltonian}\index{modular!Hamiltonian}\nomenclature{$K_{\spacetimeregion{O}}$}{modular Hamiltonian for $\spacetimeregion{O}$}
+ \emph{modular Hamiltonian}\index{modular!Hamiltonian}\nomenclature[KO]{$K_{\spacetimeregion{O}}$}{modular Hamiltonian for $\spacetimeregion{O}$}
for said region, and denoted $K_{\spacetimeregion{O}}$.
\end{definition}
@@ -472,29 +490,453 @@ In other words, $K_{\spacetimeregion{O}}$ is the unique selfadjoint operator suc
A\psi(p) = - \frac{2\pi}{i} \parens[\big]{\partial_0 \psi(p) \, p^1 + \partial_1 \psi(p) \, p^0}
\end{equation*}
\end{proposition}
+\todo{domain, proof}
\section{Complex Lorentz Transformations}
+The main result of this section is \cref{proposition:main-result}.
+
+By definition, the \emph{complex Lorentz group}\index{Lorentz group!complex}\nomenclature[LC]{$\ComplexLorentzGroup$}{complex Lorentz group} $\ComplexLorentzGroup$ is the isometry group
+of complex Minkowski space $M+iM \cong \CC^4$ with respect to the inner product
+\begin{equation*}
+ \innerp{z_1}{z_2} = \innerp{x_1}{x_2} - \innerp{y_1}{y_2} + i \parens[\big]{\innerp{x_1}{y_2} + \innerp{x_2}{y_1}}.
+\end{equation*}
+The \emph{complex Poincaré group}\index{Poincaré group!complex}\nomenclature[PC]{$\ComplexPoincareGroup$}{complex Poincaré group} is the semidirect product $\ComplexPoincareGroup \defequal \CC^4 \ltimes \ComplexLorentzGroup$.
+The action of $\ComplexPoincareGroup$ on $M+iM$ is defined in the obvious way.
+The complex Poincaré group has just two connected components, the subgroup $\ProperComplexPoincareGroup$ and the subset $\ImproperComplexPoincareTransformations$,
+differentiated by the sign of $\det \Lambda \in \braces{\pm 1}$ for its elements $(z,\Lambda)$.
+The (real) proper orthochronous Poincaré group $\ProperOrthochronousPoincareGroup$ is a subgroup of $\ProperComplexPoincareGroup$.
+Each of the two following sections deals with a subgroup $G$ of $\ProperOrthochronousPoincareGroup$,
+and the possibility of extending a unitary representation of $G$ to a larger set within $\ProperComplexPoincareGroup$.
+
\subsection{Analytic Continuation of the Space-Time Translation Group}
+%\todo{a short intro}
+
+Let $a \mapsto U(a)$ be a strongly continuous unitary representation of the additive group of $\RR^4$ (on some separable Hilbert space).
+By a generalization of Stone's Theorem~\cite[Theorem VIII.12]{ReedSimon1},
+there exists a unique projection-valued measure $E$ on $\RR^4$ such that
+\begin{equation}
+ \label{equation:spectral-resolution-translation}
+ U(a) = \int_{\RR^4} \exp(ia \cdot k) \, dE(k) \qquad a \in \RR^4.
+\end{equation}
+Then one can define a vector $P$ of unbounded selfadjoint operators
+\begin{equation*}
+ P_i = \int_{\RR^4} k_i \, dE(k) \qquad i=0,\ldots,3
+\end{equation*}
+which have a common dense domain $D$ and satisfy
+\begin{equation*}
+ a \cdot P = \int_{\RR^4} a \cdot k \, dE(k) \qquad a \in \RR^4.
+\end{equation*}
+We are specifically interested in the representation
+\begin{equation*}
+ U(a) \defequal U(a,I) \qquad a \in \RR^4
+\end{equation*}
+obtained by restricting the unitary representation of the Poincaré group $\RestrictedPoincareGroup$ on Fock space to the subgroup of spacetime translations.
+In this case the vector operator $P$ carries the physical meaning of energy-momentum,
+and we impose the so-called \emph{spectrum condition}
+\begin{equation*}
+ \langle a \cdot P \rangle_{\psi} \ge 0 \qquad
+ \forall \psi \in D \;
+ \forall a \in \ClosedForwardCone,
+\end{equation*}
+where $\ClosedForwardCone \defequal \braces{a \in \RR^4 \vcentcolon a \cdot a \ge 0, a^0 \ge 0}$ is the \emph{closed forward cone}\index{cone!closed forward}\nomenclature[V]{$\ClosedForwardCone$}{closed forward cone}.
+It can be shown \cite{Uhlmann1961} that the spectrum condition is equivalent to the statement that
+the support of the spectral measure is contained in the closed forward cone, i.e.\ $\supp(E) \subset \ClosedForwardCone$.
+
+Spectral calculus allows us to extend $a \mapsto U(a)$ to complex arguments $z \in \CC^4$ by simply replacing $a$ with $z$ in the spectral resolution~\eqref{equation:spectral-resolution-translation} of $U(a)$.
+However, one obtains, in general, an unbounded operator.
+It is a consequence of the spectrum condition that $U(z)$ is bounded whenever $z$ lies in the \emph{closed forward tube}\index{tube!closed}\nomenclature[T]{$\ClosedForwardTube$}{closed forward tube} $\ClosedForwardTube \defequal \RR^4 + i\ClosedForwardCone$.
+Observe that the set $\ClosedForwardTube$ is closed under vector addition and thus forms a commutative monoid; it is not a group.
+
+\begin{proposition}{}{}
+ For every $z \in \ClosedForwardTube$ the operator
+ \nomenclature[U]{$U(z)$}{complex translation}
+ \begin{equation}
+ \label{equation:definition-complex-translation}
+ U(z) \defequal \int_{\ClosedForwardCone} \exp(iz \cdot k) \, dE(k)
+ \end{equation}
+ is bounded.
+ Moreover, $U(w+z) = U(w) U(z)$ for all $w,z \in \ClosedForwardTube$.
+\end{proposition}
+
+\begin{proof}
+ By a general property of spectral integrals~\cite[Proposition 4.18]{Schmüdgen2012},
+ the operator $U(z)$ is bounded if (and only if)
+ the function $f(k) = \exp(iz \cdot k)$ is bounded $E$-almost everywhere.
+ In view of the fact that $E$ is supported in the closed forward cone $\ClosedForwardCone$,
+ it is sufficient to show that $f$ is bounded on $\ClosedForwardCone$.
+ %the $E$-essential supremum of the function
+ Since $z$ lies in the closed forward tube, $z=x+iy$ with $x \in \RR^4$ and $y \in \ClosedForwardCone$.
+ Now $\abs{f(k)} = \exp(-y \cdot k)$, and on $\ClosedForwardCone$ this is bounded by $1$ because $y \cdot k \ge 0$ for all $k \in \ClosedForwardCone$.
+
+ The identity $U(w+z) = U(w) U(z)$ follows from $\exp(i(w+z) \cdot k) = \exp(iw \cdot k) \exp(iz \cdot k)$
+ and the boundedness of the operators, see~\cite[Proposition 4.16(iii) and (v)]{Schmüdgen2012}.
+\end{proof}
+
+\begin{proposition}{}{}
+ If $(b,\Lambda) \in \RestrictedPoincareGroup$ and $z \in \ClosedForwardTube$, then $\Lambda z \in \ClosedForwardTube$ and
+ \begin{equation*}
+ U(b,\Lambda) U(z) U(b,\Lambda)^* = U(\Lambda z).
+ \end{equation*}
+\end{proposition}
+
+\begin{proof}
+ We exploit the uniqueness of the projection-valued measure $E$ satisfying~\eqref{equation:spectral-resolution-translation}.
+ Since $\Lambda$ acts continuously on $\RR^4$, $\Lambda^{-1} S$ is a Borel set whenever $S \subset \RR^4$ is, and
+ \begin{equation*}
+ F(S) \defequal U(b,\Lambda) E(\Lambda^{-1} S) U(b,\Lambda)^*
+ \qquad S \in \BorelSigmaAlgebra{\RR^4}
+ \end{equation*}
+ is a well-defined projection-valued measure on $\RR^4$.
+ By the Transformation Formula for Spectral Integrals~\cite[Proposition 4.24]{Schmüdgen2012}, we have
+ \begin{align}
+ \int_{\RR^4} \exp(iz \cdot k) \, dF(k)
+ &= U(b,\Lambda) \bracks[\bigg]{\,\int_{\RR^4} \!\exp(iz \cdot \Lambda k) \, dE(k)} U(b,\Lambda)^* \nonumber\\
+ &= U(b,\Lambda) \bracks[\bigg]{\,\int_{\RR^4} \!\exp(i \Lambda^{-1} z \cdot k) \, dE(k)} U(b,\Lambda)^* \nonumber\\
+ \label{equation:F-integral}
+ &= U(b,\Lambda) U(\Lambda^{-1} z) U(b,\Lambda)^*
+ \end{align}
+ for all $z \in \ClosedForwardTube$.
+ In particular, for $z=a \in \RR^4$ the last term equals
+ \begin{equation*}
+ U(b,\Lambda) U(\Lambda^{-1} a) U(b,\Lambda)^* = U(a) \qquad a \in \RR^4,
+ \end{equation*}
+ which can be seen by applying $U$ to the identity
+ \begin{equation*}
+ (b,\Lambda) (\Lambda^{-1} a, I) (b,\Lambda)^{-1} = (a,I).
+ \end{equation*}
+ Hence, $U(a) = \int \exp(ia \cdot k) dF(k)$ for all $a \in \RR^4$. We conclude $E = F$.
+ Now~\eqref{equation:F-integral} asserts that $U(z) = U(b,\Lambda) U(\Lambda^{-1} z) U(b,\Lambda)$ for all $z \in \ClosedForwardTube$
+ and a substitution of $z$ by $\Lambda z$ yields the desired identity.
+\end{proof}
+
+%\begin{proposition}{Analyticity of the Complex Translation Monoid}{analyticity-complex-translations}
+ \begin{proposition}{\textmd{\cite[Theorem 4]{Uhlmann1961}}}{analyticity-complex-translations}
+ The operator-valued map $z \mapsto U(z)$ given by~\eqref{equation:definition-complex-translation} is
+ strongly continuous on $\ClosedForwardTube$ and
+ analytic on $\OpenForwardTube$.
+\end{proposition}
+
+\todo{Explain what it means for an operator-valued function of several complex variables to be analytic.}
+
+Next we consider an operator-valued tempered distribution $u$ that is \emph{covariant}
+in the sense that it obeys the relativistic transformation law
+\begin{equation}
+ \label{equation:covariance-distribution}
+ U(g) u(f) U(g)^* = u(f_g) \qquad g \in \RestrictedPoincareGroup, f \in \schwartz{\RR^4},
+\end{equation}
+where $f_g(x) = f(g^{-1} x)$ for all $x \in M$.
+In particular, if $g=(a,I)$ is the translation by a vector $a \in \RR^4$,
+then~\eqref{equation:covariance-distribution} and the invariance of the vacuum vector $\FockVacuum$ imply
+\begin{equation}
+ \label{equation:real-translation-law}
+ U(a) u(f) \FockVacuum = u(f_a) \FockVacuum \qquad \forall a \in \RR^4.
+\end{equation}
+We would like to extend this law to complex translation vectors,
+but translating a function defined on $\RR^4$ by a complex vector is not a sensible operation.
+Nevertheless, we have $\FT{f_a}(p) = \exp(ia \cdot p) \ft{f}(p)$ in Fourier space,
+and $\exp(iz \cdot p) \ft{f}(p)$ is a well defined function of $p \in \RR^4$ even when $z \in \CC^4$.
+The obvious idea would be to define $f_z$ as the inverse Fourier transform of this function.
+This does not work because $\exp(iz \cdot p) \ft{f}(p)$ is generally not in the Schwartz class.
+However, thanks to the spectrum condition we may modify this function outside of the closed forward cone.
+
+\begin{lemma}{}{depends-only-on-restriction}
+ Let $u$ be a covariant operator-valued tempered distribution.
+ Then the vector $u(f) \FockVacuum$, where $f \in \schwartz{\RR^4}$,
+ depends only on the restriction of $\ft{f}$ to $\ClosedForwardCone$.
+\end{lemma}
+
+\begin{proof}
+ We consider a Schwartz function $g \in \schwartz{\RR^4}$ and
+ the operator $G = \int g(k) dE(k)$,
+ where $E$ is the unique projection-valued measure on $\RR^4$ such that
+ $U(a) = \int \exp(ik \cdot a) dE(k)$ for all $a \in \RR^4$.
+ Let $g(k) = (2 \pi)^{-2} \int \ift{g}(a) \exp(ia \cdot k) da$ be the Fourier decomposition of $g$.
+ \begin{multline*}
+ \hspace{1cm} (2 \pi)^2 G = \int_{\ClosedForwardCone} \!\int_{\RR} \ift{g}(a) \exp(ia \cdot k) \, da \, dE(k) = \\
+ = \int_{\RR} \ift{g}(a) \!\int_{\ClosedForwardCone} \exp(ia \cdot k) \, dE(k) \ da
+ = \int_{\RR} \ift{g}(a) U(a) \, da \hspace{1cm}
+ \end{multline*}
+ \question{Darf ich hier wirklich die Integrationsreihenfolge vertauschen?}
+
+ Recall that the Fourier transform of $u$ is defined by $\ft{u}(f) = u(\ft{f}@@)$ for $f \in \schwartz{\RR^4}$.
+ We obtain the action of the translation group on $\ft{u}(\ft{f}@@)\FockVacuum$ by definition chasing and~\eqref{equation:real-translation-law}:
+ \begin{equation*}
+ U(a) \ft{u}(\ft{f}@@)\FockVacuum
+ = U(a) u(f)\FockVacuum
+ = u(f_a)\FockVacuum
+ = \ft{u}(\ft{f}_a)\FockVacuum
+ = \ft{u}(\ft{f}e_a)\FockVacuum
+ \end{equation*}
+ Here $e_a$ stands for the function $e_a(p) = \exp(ia \cdot p)$.
+ \begin{equation*}
+ G @\ft{u}(\ft{f}@@)\FockVacuum
+ = \int \ift{g}(a) @\ft{u}(\ft{f}e_a)\FockVacuum \, da
+ = \ft{u} \parens[\bigg]{\ft{f} \int \ift{g}(a) e_a da} \FockVacuum
+ = \ft{u}(\ft{f} g) \FockVacuum
+ \end{equation*}
+ The second identity is due to the continuity of the vector-valued map $f \mapsto u(f) \FockVacuum$.
+ If the support of $g$ does not intersect the support of $E$, i.e.\ the closed forward cone, then $G=0$.
+ Thus, $\ft{u}(\ft{f} g) \FockVacuum = 0$.
+ This proves that $u(f_1) \FockVacuum = u(f_2) \FockVacuum$ when $\supp(\ft{f_1} - \ft{f_2}) \subset \ClosedForwardCone$.
+\end{proof}
+
+This fact inspires the definition
+\begin{equation*}
+ f_z \defequal d_z * f \qquad z \in \ClosedForwardTube
+\end{equation*}
+where $d_z$ is any Schwartz function on $\RR^4$ such that $\FT{d_z}(p) = \exp(iz \cdot p)$ for all $p \in \ClosedForwardCone$.
+Such a function does exist \todo{elaborate, smooth cutoff}. Then $f_z$ will be Schwartz class as well.
+Moreover, $u(f_z) \FockVacuum$ does not depend on the specific choice of $d_z$, by~\cref{lemma:depends-only-on-restriction}.
+
+%\begin{lemma}{}{}
+ %For every $z \in \ClosedForwardTube$ there exists a Schwartz function $d_z \in \schwartz{\RR^4}$
+ %such that $\ft{e_z} \in \schwartz{\RR^4}$ and $\ft{e_z}(p) = \exp(iz \cdot p)$ for $p \in \ClosedForwardCone$.
+%\end{lemma}
+
+\begin{proposition}{}{}
+ Let $u$ be a covariant operator-valued tempered distribution,
+ and let $f \in \schwartz{\RR^4}$ be a test function. Then we have,
+ in generalization of~\eqref{equation:real-translation-law},
+ \begin{equation*}
+ U(z) u(f) \FockVacuum = u(f_z) \FockVacuum \qquad \forall z \in T_+.
+ \end{equation*}
+\end{proposition}
+
+\begin{proof}
+ By \cref{proposition:analyticity-complex-translations},
+ the function $z \mapsto U(z) u(f) \FockVacuum$ is analytic on the open forward tube.
+ \todo{Zeige, dass $z \mapsto u(f_z) \FockVacuum$ ebenfalls analytisch ist.
+ Dann folgt die Behauptung wohl mit Edge of the Wedge~\cite[Theorem 2-17]{Streater1964}}
+\end{proof}
+
\subsection{Complex Lorentz Boosts}
+The Lorentz boosts $\Lambda(t)$ given by
+the matrices~\eqref{equation:lorentz-boost} in standard representation
+have a natural interpretation for complex parameters,
+since the hyperbolic functions $\cosh$ and $\sinh$ extend analytically to the whole complex plane.
+In view of Lemma xxx it follows immediately that the matrix-valued function $\CC \ni w \mapsto \Lambda(w)$ is entire analytic.
+In particular, the vector-valued function $\CC \ni w \mapsto \Lambda(w) z$ is entire analytic for every fixed vector $z \in \CC^4$.
+
+We are particularly interested in the case of a purely imaginary parameter.
+The relations $\cosh iz = \cos z$ and $\sinh iz = i \sin z$
+between the complex hyperbolic and trigonometric functions imply
+
+\begin{equation*}
+ \Lambda(is) = \begin{pmatrix}
+ \phantom{i}\cos(2 \pi @ s) & i\sin(2 \pi @ s) & \; 0 \; & \; 0 \; \\
+ i\sin(2 \pi @ s) & \phantom{i}\cos(2 \pi @ s) & 0 & 0 \\
+ 0 & 0 & 1 & 0 \\
+ 0 & 0 & 0 & 1 \\
+ \end{pmatrix}
+ \qquad \forall s \in \RR.
+\end{equation*}
+
+\begin{equation*}
+ \Lambda(is) (x+iy) =
+ \begin{pmatrix}
+ \cos(2 \pi @ s) x^0 - \sin(2 \pi @ s) y^1 \\
+ \cos(2 \pi @ s) x^1 - \sin(2 \pi @ s) y^0 \\
+ x^2 \\
+ x^3
+ \end{pmatrix}
+ +i
+ \begin{pmatrix}
+ \sin(2 \pi @ s) x^1 + \cos(2 \pi @ s) y^0 \\
+ \sin(2 \pi @ s) x^0 + \cos(2 \pi @ s) y^1 \\
+ y^2 \\
+ y^3
+ \end{pmatrix}
+\end{equation*}
+
+We
+
+\begin{equation*}
+ \mathcal{J} \defequal \Lambda(i/2) = \begin{pmatrix}
+ -1 & 0 & \; 0 \; & \; 0 \; \\
+ 0 & -1 & 0 & 0 \\
+ 0 & 0 & 1 & 0 \\
+ 0 & 0 & 0 & 1 \\
+ \end{pmatrix}
+\end{equation*}
+
+\begin{equation*}
+ \mathcal{J}_{\pm} \defequal \Lambda(\pm i/4) = \begin{pmatrix}
+ 0 & \pm i & \; 0 \; & \; 0 \; \\
+ \pm i & 0 & 0 & 0 \\
+ 0 & 0 & 1 & 0 \\
+ 0 & 0 & 0 & 1 \\
+ \end{pmatrix}
+\end{equation*}
+
+We now turn to the unitary representation of (real) Lorentz boosts
+\begin{equation*}
+ V(t) \defequal U \parens[\big]{0,\Lambda(t)} \qquad t \in \RR
+\end{equation*}
+on Fock space and aim for an analytic extension similar to the previous section.
+By Stone's theorem theorem there exists a unique selfadjoint operator $K$ such that
+\begin{equation*}
+ V(t) = \exp(itK) = \int_{\RR} \exp(it \lambda) \,dE_K(\lambda),
+\end{equation*}
+where $E_K$ is the spectral measure on $\RR$ associated to $K$.
+Now we define \emph{complex Lorentz boosts} to be the operators
+\nomenclature[V]{$V(z)$}{complex Lorentz boost}
+\begin{equation*}
+ V(z) \defequal \int_{\RR} \exp(iz \lambda) \,dE_K(\lambda) \qquad z \in \CC.
+\end{equation*}
+In contrast to the previous section, we
+
+
+\begin{lemma}{}{}
+ Suppose $A$ is a selfadjoint unbounded operator on some Hilbert space $\hilb{H}$.
+ For each complex number $z$ define the closed normal operator $V(z) = e^{izA}$ by means of functional calculus.
+ Let $g \in \schwartz{\RR}$ be a Schwartz function.
+ \begin{enumerate}
+ \item $V(z) V(w) = V(z + w)$ for all $z,w \in \CC$.
+ \item The operator $g(A)$ is bounded, and its range is contained in the domain of $V(z)$ for all $z \in \CC$.
+ \item The operator $V(z) g(A)$ is bounded for all $z \in \CC$, and has spectral resolution
+ \begin{equation*}
+ V(z) g(A) = \int e^{iz \lambda} g(\lambda) dE_A(\lambda).
+ \end{equation*}
+ \item The function $z \mapsto V(z) g(A)$ is entire analytic.
+ \end{enumerate}
+\end{lemma}
+
+Remember that a \emph{core}\index{operator!core for an} for a closed densely defined unbounded operator $T$
+is, by definition, a linear subspace $\mathcal{D}_0$ of its domain $\Domain{T}$ such that
+the closure of the restriction of $T$ to $\mathcal{D}_0$ coincides with $T$.
+%symbolically $\overline{T \vert \mathcal{D}_0} = T$.
+Each core of $T$ is necessarily a dense subspace of $\Domain{T}$,
+but a dense subspace of $\Domain{T}$ need not be a core for $T$.
+
+\begin{lemma}{A Common Core for All Complex Lorentz Boosts}{common-core-for-complex-lorentz-boots}
+ Adopt the notation of the foregoing lemma. The linear subspace
+ \begin{equation*}
+ \mathcal{D}_0 = \Span \braces{\ran g(K) \vcentcolon g \in \schwartz{\RR}}
+ \end{equation*}
+ is a core for $V(z)$ for every $z \in \CC$.
+\end{lemma}
+
+\begin{proof}
+ xxx
+\end{proof}
+
+\subsection{Application to the Energy Density}
+
+\bluetext{Achtung: Dieser Abschnitt ist noch roh, lückenhaft und enthält inkonsistente Notation und falsche Aussagen.}
+The following three Lemmas are variations of the arguments
+brought forward by~\citeauthor{Bisognano1975} in their proof of \cref{theorem:bisognano-wichmann}.
+The main difference is that we state xxx and xxx as operator identities without reference to a field operator,
+and proof xxx for arbitrary Lorentz-covariant operator-valued distributions
+rather than products of field operators.
+This generalization is necessary for the application to the energy density.
+In addition, we provide in \cref{chapter:convolution} a complete proof of the convolution formula for vector-valued distributions.
+
+Roughly speaking, the following Lemma asserts that a translation by a complex vector
+followed by a suitable imaginary boost is again a complex translation.
+
+\begin{lemma}{}{}
+Let $z = x + iy \in \OpenForwardTube$ with $x,y$ real, and suppose $y^3=y^4=0$.
+ \begin{enumerate}
+ \item If $x \in \rightwedge$, then for all $s \in [0,1/4]$
+ \begin{equation*}
+ \Lambda(is) z \in \OpenForwardTube, \qquad
+ \ran U(z) \subset \dom V(is), \qquad
+ V(is) U(z) = U \parens[\big]{\Lambda(is) z}.
+ \end{equation*}
+ \item If $x \in \leftwedge$, then the above holds for all $s \in [0,-1/4]$.
+ \end{enumerate}
+\end{lemma}
+\nomenclature[dom]{$\dom T$}{domain of the operator $T$\nomnorefpage}
+\nomenclature[ran]{$\ran T$}{range of the operator $T$\nomnorefpage}
+
+\begin{proof}
+ xxx
+
+ \noindent\begin{minipage}{0.5\textwidth}
+ The vector-valued function $\CC \ni s \mapsto \Lambda(is) z$ is entire analytic.
+ In particular it is continuous, and we have shown that it maps the compact subset $[0,1/4]$ into the open set $\OpenForwardTube$.
+ This implies that there exists a connected open neighborhood $N \subset \CC$ of $[0,1/4]$ such that $\Lambda(is) z \in \OpenForwardTube$ for all $s \in N$.
+
+ \end{minipage} \hfill
+ \begin{minipage}{0.45\textwidth}
+ \begin{center}
+ \begin{tikzpicture}[baseline=10]
+ \draw[->] (-1,0) -- (3,0) node[right] {\footnotesize$\Real s$};
+ \draw[->] (0,-1) -- (0,2) node[left] {\footnotesize$\Imag s$};
+ \draw[faunat,thick,{Parenthesis[]}-{Parenthesis[]}] (0,-0.5) -- (0,0.5);
+ \draw[thick,{Bracket[]}-{Bracket[]}] (-0.3pt,0) -- (2,0);
+ \draw (1,1) node {$N$};
+ \draw (2,0) node[above] {\footnotesize$\tfrac{1}{4}$};
+ \draw plot [smooth cycle] coordinates {(2.5,0) (2,1) (1,0.7) (0.3,1) (-0.5,0.7) (-0.3,-0.7) (1.6,-0.7)};
+ \end{tikzpicture}
+ \end{center}
+ \end{minipage}
+
+ Let $\xi \in \hilb{F}$ be arbitrary, and let $\eta$ be in the common dense domain $\mathcal{D}_0$ of the operators $V(is)$ from \cref{lemma:common-core-for-complex-lorentz-boots}.
+ Then the function $f_1(s) = \innerp{V(is)^* \eta}{U(z) \xi}$ is well-defined, and entire analytic by Lemma xxx.
+ The function $f_2(s) = \innerp{\eta}{U(\Lambda(is) z) \xi}$ is analytic on $N$, by \cref{proposition:analyticity-complex-translations}.
+ By Lemma xxx, $f_1$ and $f_2$ agree in an open real neighborhood $is$.
+ Since $N$ is an open neighborhood of $0$, there is an $\epsilon >0$ such that $i(-\epsilon,\epsilon) \subset N$.
+ It follows that $f_1 \equiv f_2$ on $N$.
+ core \ldots
+\end{proof}
+
\begin{lemma}{}{}
- Suppose $A$ is a selfadjoint operator on some Hilbert space $\hilb{H}$.
- For all complex numbers $z$ define a closed normal operator $V(z) = e^{izA}$ by means of functional calculus.
- Let $g$ be a xxx function. Then the range of the bounded operator $g(A)$ is contained in the domain of $V(z)$ for all $z$, and
+ Let $x \in \rightwedge$
+\begin{equation*}
+ \stronglim_{\varepsilon \downarrow 0} V(i/4) U(x+i \varepsilon e_0)
+ = U \parens[\big]{V(i/4)x}
+ = \stronglim_{\varepsilon \downarrow 0} V(-i/4) U(\mathcal{J}x+i \varepsilon e_0)
+\end{equation*}
+\end{lemma}
+
+\begin{proof}
+ xxx
+\end{proof}
+
+\begin{lemma}{}{}
+ Suppose that $u$ is a covariant operator-valued tempered distribution.
+ Let $f \in \schwartz{M}$ with $\supp f \subset \rightwedge$, and
+ let $g \in \schwartz{M}$ be arbitrary. Then
\begin{equation*}
- V(z) g(A) = \int e^{iz \lambda} g(\lambda) dE_A(\lambda).
+ V(i/2) g(K) u(f) \FockVacuum = g(K) u(f_{\mathcal{J}}) \FockVacuum
\end{equation*}
\end{lemma}
-\subsection{A Convolution Theorem for Vector-Valued Tempered Distributions}
+Here, $K$ is the infinitesimal generator of the group $t \mapsto V(t)$ of real Lorentz boosts,
+$\FockVacuum$ is the Fock vacuum, and $\mathcal{J}$ is the Lorentz transformation given by the diagonal matrix $\diag(-1,-1,1,1)$.
-\blockcquote{Bisognano1975}{%
- The extension to vector-valued tempered distributions is trivial.
-}
+\begin{proof}
+ xxx
+\end{proof}
+
+\begin{equation*}
+ \Delta^{-1/2} g(K) \energydensity(f) \FockVacuum = g(K) \energydensity(f^J) \FockVacuum
+\end{equation*}
+
+Die Anwendung auf die Energiedichte $\energydensity$:
+
+\begin{proposition}{}{main-result}
+ Suppose $W \subset M$ is any wedge domain, with associated modular operator $\Delta_W$ and modular Hamiltonian $K_W$.
+ Let $f \in \schwartz{M}$ with $\supp f \subset W$, and
+ let $h \in \schwartz{M}$ be arbitrary. Then
+ \begin{equation*}
+ \norm{\Delta_W^{-1/2} h(K_W) \energydensity(f) \FockVacuum}
+ = \norm{h(K) \energydensity(f_{\mathcal{J}g}) \FockVacuum},
+ \end{equation*}
+ where $K$ is the modular Hamiltonian of the right wedge $\rightwedge$,
+ and $g$ is any element of $\RestrictedPoincareGroup$ such that $W = g \rightwedge$,
+ and $\mathcal{J} = \diag(-1,-1,1,1)$.
+\end{proposition}
+In der Ungleichung aus~\cite{Much2022} ist $h$ eine Gauß-Funktion.
+
+\section{Calculating Gaussians of the Modular Hamiltonian}
+coming soon\ldots
\chapterbib
\cleardoublepage
diff --git a/preamble.tex b/preamble.tex
index 35d94ad..8479b31 100644
--- a/preamble.tex
+++ b/preamble.tex
@@ -11,9 +11,12 @@
\usepackage{amsmath,amsthm}
\usepackage{mathtools}
\usepackage[colon=literal]{unicode-math} % TODO get rid of this since it messes up math italic correction
-\usepackage{enumitem}
+\usepackage[inline]{enumitem}
+\usepackage{multicol}
%\usepackage{graphicx}
+\usepackage{tikz}
\usepackage{tcolorbox}
+%\usepackage{wrapfig}
\usepackage[style=ext-alphabetic]{biblatex}
\usepackage[intoc,refpage]{nomencl}
\usepackage{makeidx}
@@ -81,8 +84,10 @@
% ---------- amsmath
\numberwithin{equation}{chapter}
\DeclareMathOperator{\supp}{supp}
+\DeclareMathOperator{\diag}{diag}
\DeclareMathOperator{\dom}{dom}
\DeclareMathOperator{\ran}{ran}
+\DeclareMathOperator{\Span}{span}
% extend amsmath's proof environment
\NewDocumentEnvironment{myproof}{Ob}{\IfNoValueTF{#1}{\begin{proof}}{\begin{proof}[\proofname\ of \Cref{#1}]}}{\end{proof}}
@@ -99,6 +104,12 @@
\DeclarePairedDelimiterX\innerp[2]{\langle}{\rangle}{#1,#2}
\DeclarePairedDelimiterX\LorentzBF[2]{\lparen}{\rparen}{#1,#2}
+% ---------- enumitem
+\setlist[enumerate,1]{label=(\roman*),nosep,leftmargin=*,widest=ii}
+
+% ---------- tikz
+\usetikzlibrary{arrows.meta}
+
% ---------- tcolorbox
\tcbuselibrary{skins,theorems,breakable} % add breakable library?
\tcbset{%
@@ -177,7 +188,9 @@
% ---------- nomencl
\makenomenclature
-\renewcommand*{\nomname}{List of Symbols}
+\renewcommand{\nomname}{List of Symbols}
+\renewcommand{\nompreamble}{\begin{multicols}{2}}
+\renewcommand{\nompostamble}{\end{multicols}}
%\def\pagedeclaration#1{, \hyperlink{page.#1}{page\nobreakspace#1}}
\def\pagedeclaration#1{, \hyperlink{page.#1}{#1}}
@@ -234,6 +247,7 @@
% TODO Why does this not work?
\renewcommand{\Re}{\operatorname{Re}}
\renewcommand{\Im}{\operatorname{Im}}
+\newcommand{\Real}{\operatorname{Re}}
\newcommand{\Imag}{\operatorname{Im}}
% emphasis for defined terms
@@ -283,6 +297,7 @@
\newcommand*{\BosonFockFinite}[1]{\mathcal{F}^{@0}_{\!\ts{s}}(#1)}
\newcommand*{\FermionFock}[1]{\mathcal{F}_{\!\ts{s}}(#1)}
\newcommand*{\FermionFockFinite}[1]{\mathcal{F}^{@0}_{\!\ts{s}}(#1)}
+\newcommand*{\FockVacuum}{\Omega}
% Operators
% ---------
@@ -320,27 +335,65 @@
\newcommand{\defequal}{\overset{\text{\scriptsize def}}{=}}
\newcommand*{\energydensity}{\varrho}
-\newcommand*{\fockvaccum}{\Omega}
% Observable Algebras
\newcommand*{\vNa}[1]{\mathcal{#1}}
\newcommand*{\localalg}[1]{\vNa{R}(#1)}
+% Measure Theroy
+\newcommand*{\BorelSigmaAlgebra}[2][]{\mathfrak{B}\parens[#1]{#2}}
+
+% Lorentz and Poincaré groups, subgroups and connected components
+\newcommand*{\LorentzGroup}{\mathcal{L}}
+\newcommand*{\FullLorentzGroup}{\LorentzGroup}
+\newcommand*{\ProperLorentzGroup}{\LorentzGroup_{+}}
+\newcommand*{\OrthochronousLorentzGroup}{\LorentzGroup^{\uparrow}}
+\newcommand*{\OrthochorousLorentzGroup}{\LorentzGroup_0}
+\newcommand*{\ProperOrthochronousLorentzGroup}{\LorentzGroup_{+}^{\uparrow}}
+\newcommand*{\RestrictedLorentzGroup}{\ProperOrthochronousLorentzGroup}
+\newcommand*{\ImproperOrthochronousLorentzTransformations}{\LorentzGroup_{-}^{\uparrow}}
+\newcommand*{\ProperNonorthochronousLorentzTransformations}{\LorentzGroup_{+}^{\downarrow}}
+\newcommand*{\ImproperNonorthochronousLorentzTransformations}{\LorentzGroup_{-}^{\downarrow}}
+
+\newcommand*{\ComplexLorentzGroup}{\LorentzGroup(\CC)}
+\newcommand*{\FullComplexLorentzGroup}{\ComplexLorentzGroup}
+\newcommand*{\ProperComplexLorentzGroup}{\ProperLorentzGroup(\CC)}
+\newcommand*{\ImproperComplexLorentzTransformations}{\LorentzGroup_{-}(\CC)}
+
+\newcommand*{\PoincareGroup}{\mathcal{P}}
+\newcommand*{\FullPoincareGroup}{\PoincareGroup}
+\newcommand*{\ProperPoincareGroup}{\PoincareGroup_{\!+}}
+\newcommand*{\OrthochronousPoincareGroup}{\PoincareGroup^{\uparrow}}
+\newcommand*{\OrthochorousPoincareGroup}{\PoincareGroup_0}
+\newcommand*{\ProperOrthochronousPoincareGroup}{\PoincareGroup_{\!+}^{\uparrow}}
+\newcommand*{\RestrictedPoincareGroup}{\ProperOrthochronousPoincareGroup}
+\newcommand*{\ImproperOrthochronousPoincareTransformations}{\PoincareGroup_{\!-}^{\uparrow}}
+\newcommand*{\ProperNonorthochronousPoincareTransformations}{\PoincareGroup_{\!+}^{\downarrow}}
+\newcommand*{\ImproperNonorthochronousPoincareTransformations}{\PoincareGroup_{\!-}^{\downarrow}}
+
+\newcommand*{\ComplexPoincareGroup}{\PoincareGroup(\CC)}
+\newcommand*{\FullComplexPoincareGroup}{\ComplexPoincareGroup}
+\newcommand*{\ProperComplexPoincareGroup}{\ProperPoincareGroup(\CC)}
+\newcommand*{\ImproperComplexPoincareTransformations}{\PoincareGroup_{\!-}(\CC)}
+
+% Functional Analysis
+\newcommand*{\BoundedLinearOperators}[2][]{B\parens[#1]{#2}}
+\DeclareMathOperator*{\stronglim}{s-lim}
+\DeclareMathOperator*{\weaklim}{w-lim}
-\newcommand*{\FullLorentzGroup}{\mathcal{L}}
-\newcommand*{\ProperOrthochronousLorentzGroup}{\FullLorentzGroup_{+}^{\uparrow}}
-\newcommand*{\FullPoincareGroup}{\mathcal{P}}
-\newcommand*{\ProperOrthochronousPoincareGroup}{\FullPoincareGroup_{+}^{\uparrow}}
-
-% spacetime domains
+% spacetime regions
\newcommand*{\spacetimeregion}[1]{\mathcal{#1}}
\newcommand*{\rightwedge}{W_{\! R}}
\newcommand*{\leftwedge}{W_{\! L}}
+\newcommand*{\OpenForwardCone}{V_+}
+\newcommand*{\ClosedForwardCone}{\bar{V}_+}
+\newcommand*{\OpenForwardTube}{T_+}
+\newcommand*{\ClosedForwardTube}{\bar{T}_+}
-\newcommand*{\todo}[1]{{\color{blue}TODO: #1}}
-\newcommand*{\question}[1]{{\color{blue}Question: #1}}
-\newcommand*{\info}[1]{{\color{blue}Info: #1}}
+% comments
+\newcommand*{\bluetext}[1]{{\color{blue}#1}}
+\newcommand*{\todo}[1]{\bluetext{TODO: #1}}
+\newcommand*{\question}[1]{\bluetext{Question: #1}}
+\newcommand*{\info}[1]{\bluetext{Info: #1}}
\newcommand*{\operatorclosure}[1]{\overline{#1}}
-
-\DeclareMathOperator*{\stronglim}{s-lim}
diff --git a/stresstensor.tex b/stresstensor.tex
index 4c128c2..79c0930 100644
--- a/stresstensor.tex
+++ b/stresstensor.tex
@@ -32,7 +32,9 @@ as a service to the reader.
x \cdot y = g_{\mu \nu} x^{\mu} y^{\nu} = x^0y^0 - x^1 y^1 - x^2 y^2 - x^3 y^3
\end{equation*}
points $x = (x^0,x^1,x^2,x^3) \in M$ are sometimes written $x = (x^0,\symbfit{x})$ with separated time and space coordinates
- \item Given a complex-valued function $f$ on $M$, we define its \emph{Fourier transform} $\ft{f}\,$ by
+ \item Given a complex-valued function $f$ on $M$,
+ we define its \emph{Fourier transform}\index{Fourier transform} $\ft{f}\,$ by
+ \nomenclature[f]{$\ft{f}$}{Fourier transform of $f$}
\begin{equation}
\label{fourier-transform}
\ft{f}(p) \defequal \int_{M} e^{i p \cdot x} f(x) \, dx
@@ -93,7 +95,7 @@ as a service to the reader.
\begin{equation*}
\realschwartz{M} \ni f \mapsto \varphi(f) = \Phi_{\mathrm{S}}(Ef) = \frac{1}{\sqrt{2}} \parens*{a(Ef) + a(Ef)^\dagger}
\end{equation*}
- This extedns to complex valued test functions $f \in \schwartz{M}$
+ This extends to complex valued test functions $f \in \schwartz{M}$
\begin{equation*}
\varphi(f) = \frac{1}{\sqrt{2}} \parens*{a(E\bar{f}) + a(Ef)^\dagger}
\end{equation*}
@@ -243,7 +245,7 @@ but one may obtain an operator with trivial domain.
We will use the symbol $\QFequal$ between quadratic forms or operators
to indicate their equality as quadratic forms.
-TODO(statement about domains?)
+\todo{statement about domains?}
A natural question is how the smeared operators relate to the pointwise ones.
@@ -287,7 +289,7 @@ for all $\psi,\psi' \in D$.
The process of renormalizing a product of field operators
has the purpose of discarding infinite constants
that occur when calculating the vacuum expectation value.
-(TODO: present physicists way of introducing normal ordering)
+\todo{present physicists way of introducing normal ordering}
Now let us extract the algebraic essence of the situation.
The objects of our calculations are the field operators $\Phi(f)$,
@@ -314,7 +316,7 @@ freely generated by the elements of $\hilb{H}$.
The unit of the algebra is $e$.
This in not quite what we want
-TODO(explain need for commutation relations)
+\todo{explain need for commutation relations}
By abstract algebra, this is viable
by forming the quotient of the free algebra
with respect to the two-sided ideal
@@ -332,7 +334,7 @@ where $z,z' \in \hilb{H}$.
where $e$ is the unit of the algebra.
\end{definition}
-TODO(introduce $\Phi$ as representation of $\WeylAlg$)
+\todo{introduce $\Phi$ as representation of $\WeylAlg$}
\begin{definition}{Annihilator and Creator}{}
Suppose $\WeylAlg$ is the infinitesimal Weyl algebra
@@ -383,8 +385,8 @@ The cases $r=1$ and $r=2$ read
\normord{z} &=
\frac{1}{\sqrt{2}} \parens[\big]{\weylannihilator(z) + \weylcreator(z)} = z, \\
\normord{z_1 z_2} &= \frac{1}{2}
- \parens[\big]{ \weylannihilator(z_1) \weylannihilator(z_2) + \weylcreator(z_1) \weylannihilator(z_2)
- + \weylcreator(z_2) \weylannihilator(z_1) + \weylcreator(z_1) \weylcreator(z_2) }.
+ \parens[\big]{\weylannihilator(z_1) \weylannihilator(z_2) + \weylcreator(z_1) \weylannihilator(z_2)
+ + \weylcreator(z_2) \weylannihilator(z_1) + \weylcreator(z_1) \weylcreator(z_2)}.
\end{align*}
This suggests that the normally ordered product $\normord{z_1 \!\cdots z_r}$
is symmetric in $z_1,\ldots,z_n$. This is in fact true, and becomes evident
@@ -399,7 +401,7 @@ if one brings~\eqref{equation:normal-ordering} into the equivalent form
\prod_{i=1\vphantom{S}}^{s} \weylcreator(z_{\sigma(i)})
\prod_{\mathclap{j=s+1\vphantom{S}}}^{r} \weylannihilator(z_{\sigma(j)})
\end{gather}
-by basic combinatorial arguments (TODO: further explanation?).
+by basic combinatorial arguments \todo{further explanation?}.
In~\cite{Klein1973}, the factor $\frac{1}{s!(r-s)!}$ is erroneously missing.
@@ -488,7 +490,7 @@ In terms of creation and annihilation operators we have
\label{derivative-free-field}
D \varphi(f) = \frac{1}{\sqrt{2}} \parens*{a(ED^{\dagger}f)^{\dagger} + a(E\overline{D^{\dagger}f})}.
\end{equation}
-In Fourier space the operator $D^\dagger$ corresponds to muliplication with the polynomial
+In Fourier space the operator $D^\dagger$ corresponds to multiplication with the polynomial
\begin{equation*}
\ft{D}(p) \defequal \sum_{\alpha} i^{\abs{\alpha}} a_{\alpha} (+p^0)^{\alpha_0} (-p^1)^{\alpha_1} (-p^2)^{\alpha_2} (-p^3)^{\alpha_3}
\end{equation*}
@@ -562,7 +564,7 @@ this approach incurs significant technical difficulties.
\end{lemma}
Note that $K$ has a remaining dependence on $f$ via $\chi$
-even thogh the notation does not indicate this.
+even though the notation does not indicate this.
This is made explicit in the alternative integral representation
\begin{equation}
\label{equation:alternative-integral-representation}
@@ -663,7 +665,7 @@ The following assertion is key to realizing the idea of taking the limit $f \to
C \norm{(1+H)^l \psi'} \norm{(1+H)^l \psi}.
\end{equation*}
More specifically, it is sufficient to choose $l > rd + r/2$,
- where $d$ is the highest order of differentiation occuring in $D_1, \ldots, D_r$.
+ where $d$ is the highest order of differentiation occurring in $D_1, \ldots, D_r$.
\end{lemma}
The Hamilton operator $H$ acts on $n$-particle states $\psi_n$ as follows:
@@ -869,7 +871,7 @@ In the following proof it will be convenient to use the abbreviation
\sqrt{\sum_{m=0}^{\infty} \norm{(1+H)^l \psi'_m}_2^2} =
\sqrt{\sum_{m=0}^{\infty} a'^2_m},
\end{equation*}
- and similar for $\psi$, by definition of the inner prouct
+ and similar for $\psi$, by definition of the inner product
and because $((1+H)^l \psi')_m = (1+H)^l \psi'_m$ for all $m$.
\end{myproof}
@@ -898,7 +900,7 @@ In the following proof it will be convenient to use the abbreviation
by \cref{lemma:integral-kernel-h-bound}.
Moreover, the integrand converges pointwise to $K_{\psi'\!,\psi}(p_1,\ldots,p_r)$, since $\ft{f} \to 1$ when $f \to \delta_x$.
- TODO(With of choice of FT constants, $\ft{f} \to 1/(2\pi)^2$. Change here or change def?)
+ \todo{With of choice of FT constants, $\ft{f} \to 1/(2\pi)^2$. Change here or change def?}
Since the Fourier transformation of tempered distribution
is a continuous mapping $\tempdistribnoarg \to \tempdistribnoarg$,
@@ -1076,9 +1078,9 @@ where
\end{proposition}
\begin{proposition}{}{}
- The Fock vaccum $\fockvaccum$ lies in the domain of $\energydensity(f)\QFop{}$
+ The Fock vacuum $\FockVacuum$ lies in the domain of $\energydensity(f)\QFop{}$
for all test functions $f \in \schwartz{M}$
- and $\energydensity(f)\QFop{}\fockvaccum$ is the vector $\psi$ defined by
+ and $\energydensity(f)\QFop{}\FockVacuum$ is the vector $\psi$ defined by
\begin{equation*}
\psi_2(p,p') = \frac{\sqrt{2}}{4} (m^2 - \bar{p} \cdot p') \ft{f}(-p-p')
\end{equation*}
@@ -1124,7 +1126,7 @@ where
Then we obtain the desired $H$-bound with $l=a+r/2$.
Recall that the Schwartz class is preserved by Fourier transform, translation and multiplication with polynomials.
- Moreover, it is well known that Schwartz functions are square-integrable with repect to the Lorentz invariant measure on the mass shell.
+ Moreover, it is well known that Schwartz functions are square-integrable with respect to the Lorentz invariant measure on the mass shell.
Hence,
\begin{equation*}
\int dp_1 \abs{\ft{f}(p_1 + \cdots + p_s - p_{s+1} - \cdots - p_r)}^2