ncg

bachelorthesis in physics
git clone git://popovic.xyz/ncg.git
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commit 676f03b1300224c2aef5fe512da0d86aa0c46988
parent f4c253f98f2b65a21125c0aeb306bce96475dcdc
Author: miksa234 <milutin@popovic.xyz>
Date:   Mon, 17 May 2021 15:21:39 +0200

add some more content to week8 changed cover page

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Mpdfs/week1.pdf | 0
Mpdfs/week2.pdf | 0
Mpdfs/week3.pdf | 0
Mpdfs/week4.pdf | 0
Mpdfs/week5.pdf | 0
Mpdfs/week6.pdf | 0
Mpdfs/week7.pdf | 0
Mpdfs/week8.pdf | 0
Msrc/week1.tex | 13+++++++------
Msrc/week2.tex | 12++++++++----
Msrc/week3.tex | 14++++++++------
Msrc/week4.tex | 12+++++++-----
Msrc/week5.tex | 12++++++++----
Msrc/week6.tex | 14+++++++++-----
Msrc/week7.tex | 13+++++++------
Msrc/week8.tex | 160++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
16 files changed, 204 insertions(+), 46 deletions(-)

diff --git a/pdfs/week1.pdf b/pdfs/week1.pdf Binary files differ. diff --git a/pdfs/week2.pdf b/pdfs/week2.pdf Binary files differ. diff --git a/pdfs/week3.pdf b/pdfs/week3.pdf Binary files differ. diff --git a/pdfs/week4.pdf b/pdfs/week4.pdf Binary files differ. diff --git a/pdfs/week5.pdf b/pdfs/week5.pdf Binary files differ. diff --git a/pdfs/week6.pdf b/pdfs/week6.pdf Binary files differ. diff --git a/pdfs/week7.pdf b/pdfs/week7.pdf Binary files differ. diff --git a/pdfs/week8.pdf b/pdfs/week8.pdf Binary files differ. diff --git a/src/week1.tex b/src/week1.tex @@ -73,16 +73,17 @@ \newtheorem*{idea}{Proof Idea} - - -\title{Notes on \\ Noncommutative Geometry and Particle Physics} -\author{Popovic Milutin} +\title{University of Vienna\\ Faculty of Physics\\ \vspace{1.25cm} +Notes on\\ Noncommutative Geometry and Particle Phyiscs} \date{Week 1: 05.02 - 12.02} +\author{Milutin Popovic \\ Supervisor: Dr. Lisa +Glaser} \begin{document} -\maketitle -\tableofcontents + \maketitle + \tableofcontents + \newpage \section{Noncommutative Geometric Spaces} \subsection{Matrix Algebras and Finite Spaces} diff --git a/src/week2.tex b/src/week2.tex @@ -73,14 +73,18 @@ \newtheorem*{idea}{Proof Idea} -\title{Notes on \\ Noncommutative Geometry and Particle Physics} -\author{Popovic Milutin} + +\title{University of Vienna\\ Faculty of Physics\\ \vspace{1.25cm} +Notes on\\ Noncommutative Geometry and Particle Phyiscs} +\author{Milutin Popovic \\ Supervisor: Dr. Lisa +Glaser} \date{Week 2: 12.02 - 19.02} \begin{document} -\maketitle -\tableofcontents + \maketitle + \tableofcontents + \newpage \section{Noncommutative Geometric Spaces} \subsection{Noncommutative Matrix Algebras} diff --git a/src/week3.tex b/src/week3.tex @@ -37,15 +37,17 @@ \newtheorem*{idea}{Proof Idea} - -\title{Notes on \\ Noncommutative Geometry and Particle Physics} -\author{Popovic Milutin} -\date{Week 2: 26.02 - 4.03} +\title{University of Vienna\\ Faculty of Physics\\ \vspace{1.25cm} +Notes on\\ Noncommutative Geometry and Particle Phyiscs} +\author{Milutin Popovic \\ Supervisor: Dr. Lisa +Glaser} +\date{Week 3: 26.02 - 4.03} \begin{document} -\maketitle -\tableofcontents + \maketitle + \tableofcontents + \newpage \section{Excurse to Group Theory and Lie Groups} \subsection{Groups and Representations} \begin{definition} diff --git a/src/week4.tex b/src/week4.tex @@ -37,15 +37,17 @@ \newtheorem*{idea}{Proof Idea} - -\title{Notes on \\ Noncommutative Geometry and Particle Physics} -\author{Popovic Milutin} +\title{University of Vienna\\ Faculty of Physics\\ \vspace{1.25cm} +Notes on\\ Noncommutative Geometry and Particle Phyiscs} +\author{Milutin Popovic \\ Supervisor: Dr. Lisa +Glaser} \date{Week 4: 05.03 - 12.03} \begin{document} -\maketitle -\tableofcontents + \maketitle + \tableofcontents + \newpage \section{Characters} \begin{definition} diff --git a/src/week5.tex b/src/week5.tex @@ -74,14 +74,18 @@ \newtheorem*{idea}{Proof Idea} -\title{Notes on \\ Noncommutative Geometry and Particle Physics} -\author{Popovic Milutin} + +\title{University of Vienna\\ Faculty of Physics\\ \vspace{1.25cm} +Notes on\\ Noncommutative Geometry and Particle Phyiscs} +\author{Milutin Popovic \\ Supervisor: Dr. Lisa +Glaser} \date{Week 5: 12.03 - 19.03} \begin{document} -\maketitle -\tableofcontents + \maketitle + \tableofcontents + \newpage \section{Noncommutative Geometric Spaces } \subsection{Exercises} diff --git a/src/week6.tex b/src/week6.tex @@ -73,16 +73,20 @@ \newtheorem*{idea}{Proof Idea} +\date{Week 6: 19.03 - 26.03} -\title{Notes on \\ Noncommutative Geometry and Particle Physics} -\author{Popovic Milutin} +\title{University of Vienna\\ Faculty of Physics\\ \vspace{1.25cm} +Notes on\\ Noncommutative Geometry and Particle Phyiscs} +\author{Milutin Popovic \\ Supervisor: Dr. Lisa +Glaser} \date{Week 6: 19.03 - 26.03} -\begin{document} -\maketitle -\tableofcontents +\begin{document} + \maketitle + \tableofcontents + \newpage \section{Finite Real Noncommutative Spaces} \subsection{Finite Real Spectral Triples} Add on to finite real spectral triples a \textit{real structure}. The diff --git a/src/week7.tex b/src/week7.tex @@ -79,16 +79,17 @@ \newtheorem*{idea}{Proof Idea} - -\title{Notes on \\ Noncommutative Geometry and Particle Physics} -\author{Popovic Milutin} +\title{University of Vienna\\ Faculty of Physics\\ \vspace{1.25cm} +Notes on\\ Noncommutative Geometry and Particle Phyiscs} +\author{Milutin Popovic \\ Supervisor: Dr. Lisa +Glaser} \date{Week 7: 23.04 - 27.04} \begin{document} -\maketitle -\tableofcontents - + \maketitle + \tableofcontents + \newpage \section{Classification of Finite Real Spectral Triples} Here we classify finite real spectral triples modulo unitary equivalence with diff --git a/src/week8.tex b/src/week8.tex @@ -79,18 +79,22 @@ \newtheorem*{idea}{Proof Idea} -\title{Notes on \\ Noncommutative Geometry and Particle Physics} -\author{Popovic Milutin} -\date{Week 6: 19.03 - 26.03} +\title{University of Vienna\\ Faculty of Physics\\ \vspace{1.25cm} +Notes on\\ Noncommutative Geometry and Particle Phyiscs} +\author{Milutin Popovic \\ Supervisor: Dr. Lisa +Glaser} +\date{Week 8: 8.05 - 18.05} \begin{document} \maketitle \tableofcontents + \newpage + \section{Excurse} \textbf{Manifold:} A topological space that is locally Euclidean. \newline - \textbf{Riemannian Manifold:}A Manifold equipped with a riemannian + \textbf{Riemannian Manifold:}A Manifold equipped with a Riemannian Metric, a symmetric bilinear form on Vector Fields $\Gamma(TM)$ \begin{align} @@ -136,7 +140,7 @@ $(S, J_M)$ is called the \textbf{spin Structure on $M$} \newline $J_M$ is called the \textbf{charge conjugation}. - \section{Noncommutative Geomtery of Electrodynamics} + \section{Noncommutative Geometry of Electrodynamics} \subsection{The Two-Point Space} Consider a two point space $X := \{x, y\}$. This space=an be described with @@ -288,7 +292,7 @@ \begin{align} \alpha(a) = u a u^* \;\;\; \text{for} \;\; U(A) \end{align} - where $U(\mathfrak{A})$ is + where $U(A)$ is \begin{align} U(A) = \{ u\in A|\;\; uu^* = u^*u=1\} \;\;\; \text{(unitary)} @@ -337,7 +341,9 @@ Now we need to find the exact from of the field $B_\mu$ to calculate the spectral action of a spectral triple. Since $(A_F)_{J_F} \simeq \mathbb{C}$ we find that $\mathfrak{h}(F) = \mathfrak{u}((A_F)_{J_F}) - \simeq i\mathbb{R}$.\newline + \simeq i\mathbb{R}$. Where $\mathfrak{h}(F)$ is the Lie Algebra on $F$ + and $\mathfrak{u}((A_F)_{J_F})$ is the Lie algebra of the unitary group + $(A_F)_{J_F}$.\newline An arbitrary hermitian field $A_\mu = -ia\partial _\mu b$ is given by two @@ -381,7 +387,7 @@ gravity and electrodynamics although in the classical level. The almost commutative Manifold $M\times F_X$ describes a local gauge group $U(1)$. The inner fluctuations of the Dirac operator describe $Y_\mu$ the -gauge field of $U(1)$. There arrise two Problems: +gauge field of $U(1)$. There arise two Problems: \newline (1): With $F_X$, $D_F$ must vanish, however this implies that the electrons are massless (this we do not want) @@ -505,7 +511,7 @@ with two nodes of multiplicity two Add a non-zero Dirac Operator to $F_{ED}$. From the Krajewski Diagram, we see that edges only exist between the multiple vertices. So we construct a Dirac operator mapping between the two vertices. -\begin{align} +\begin{align}\label{dirac} D_F = \begin{pmatrix} 0 & d & 0 & 0 \\ @@ -545,7 +551,7 @@ and the other one acting on $L^2(S) \otimes H_{\bar{e}}$ The derivation of the gauge theory is the same for $F_{ED}$ as for $F_X$, we have $\mathfrak{B}(F) \simeq U(1)$ and for $B_\mu = A_\mu - J_F A_\mu J_F^{-1}$ -\begin{align} +\begin{align} \label{field} B_\mu = \begin{pmatrix} Y_\mu & 0 & 0 & 0 \\ @@ -569,5 +575,139 @@ distance. even thought we have infinite distance between the same manifold? What do we get if we fix this? \end{question} +\subsection{The Spectral Action} +Here we calculate the Lagrangian of the almost commutative Manifold $M\times +F_{ED}$, which corresponds to the Lagrangian of Electrodynamics on a curved +background Manifold (+ gravitational Lagrangian). It consists of the spectral +action $S_b$ (bosonic) and of the fermionic action $S_f$. + +The simples spectral action of a spectral triple $(A, H, D)$ is given by the +trace of some function of $D$, we also allow inner fluctuations of the Dirac +operator $D_\omega = D + \omega + \varepsilon' J\omega J^{-1}$ where $\omega = +\omega ^* \in \Omega_D^1(A)$. +\begin{definition} + Let $f:\mathbb{R} \rightarrow \mathbb{R}$ be a suitable function + \textbf{positive and even}. The spectral action is then + \begin{align} + S_b [\omega] := \text{Tr}f(\frac{D_\omega}{\Lambda}) + \end{align} + where $\Lambda$ is a real cutoff parameter. The minimal condition on $f$ + is that $f(\frac{D_\omega}{\Lambda})$ is a traclass operator, which mean + that it should be compact operator with well defined finite trace + independent of the basis. The subscript $b$ of $S_b$ refers to bosonic, + because in physical applications $\omega$ will describe bosonic fields. + + Furthermore there is a topological spectral action, defined with the + grading $\gamma$ + \begin{align} + S_{\text{top}}[\omega] := \text{Tr}(\gamma\ + f(\frac{D_\omega}{\Lambda})). + \end{align} +\end{definition} +\begin{definition} + The fermionic action is defined by + \begin{align} + S_f[\omega, \psi] = (J\tilde{\psi}, D_\omega \tilde{\psi}) + \end{align} + with $\tilde{\psi} \in H_{cl}^+ := \{\tilde{\psi}: \psi \in H^+\}$. + $H_{cl}^+$ is the set of Grassmann variables in $H$ in the +1-eigenspace + of the grading $\gamma$. +\end{definition} +The grasmann variables are a set of Basis vectors of a vector space, they +form a unital algebra over a vector field say $V$ where the generators are anti commuting, that is for +$\theta _i, \theta _j$ some Grassmann variables we have +\begin{align} + &\theta _i \theta _j = -\theta _j \theta _i \\ + &\theta _i x = x\theta _j \;\;\;\; x\in V \\ + &(\theta_i)^2 = 0 \;\;\; (\theta _i \theta _i = -\theta _i \theta _i) +\end{align} +\begin{proposition} + The spectral action of the almost commutative manifold $M$ with $\dim(M) + =4$ with a fluctuated Dirac operator is. + \begin{align} + \text{Tr}(f\frac{D_\omega}{\Lambda}) \sim \int_M \mathcal{L}(g_{\mu\nu}, + B_\mu, \Phi) \sqrt{g}\ d^4x + O(\Lambda^{-1}) + \end{align} + with + \begin{align} + \mathcal{L}(g_{\mu\nu}, B_\mu, \Phi) = + N\mathcal{L}_M(g_{\mu\nu}) + \mathcal{L}_B(B_\mu)+ + \mathcal{L}_\phi(g_{\mu\nu}, B_\mu, \Phi) + \end{align} + where $N=4$ and $\mathcal{L}_M$ is the Lagrangian of the spectral triple + $(C^\infty(M) , L^2(S), D_M)$ + \begin{align}\label{lagr} + \mathcal{L}_M(g_{\mu\nu}) := \frac{f_4 \Lambda ^4}{2\pi^2} - + \frac{f_2 \Lambda^2}{24\pi ^2}s - \frac{f(0)}{320\pi^2} C_{\mu\nu + \varrho \sigma}C^{\mu\nu \varrho \sigma}. + \end{align} + Here $C^{\mu\nu \varrho \sigma}$ is defined in terms of the Riemannian + curvature tensor $R_{\mu\nu \varrho \sigma}$ and the Ricci tensor + $R_{\nu\sigma} = g^{\mu\varrho} R_{\mu\nu \varrho\sigma}$. + + Furthermore $\mathcal{L}_B$ describes the kinetic term of the gauge field + \begin{align} + \mathcal{L}_B(B_\mu) := \frac{f(0)}{24\pi^2} + \text{Tr}(F_{\mu\nu}F^{\mu\nu}). + \end{align} + Last $\mathcal{L}_\phi$ is the scalar-field Lagrangian with a boundary + term. + \begin{align} + \mathcal{L}_\phi(g_{\mu\nu}, B_\mu, \Phi) := + &-\frac{2f_2\Lambda^2}{4\pi^2}\text{Tr}(\Phi^2) + \frac{f(0)}{8\pi^2} + \text{Tr}(\Phi^4) + \frac{f(0)}{24\pi^2} \Delta(\text{Tr}(\Phi^2))\\ + &+ \frac{f(0)}{48\pi^2}s\text{Tr}(\Phi^2) + \frac{f(0)}{8\pi^2}\text{Tr}((D_\mu \Phi)(D^\mu \Phi)). + \end{align} +\end{proposition} +\begin{proof} + Will maybe be filled in if I go through the last two chapters in the + book and understand the proof. +\end{proof} + +Here on we go and calculate the spectral action of $M\times F_{ED}$ +\begin{proposition} + The Spectral action of $M\times F_{ED}$ is + \begin{align} + \text{Tr}(f\frac{D_\omega}{\Lambda}) \sim \int_M \mathcal{L}(g_{\mu\nu}, + Y_\mu) \sqrt{g}\ d^4x + O(\Lambda^{-1}) + \end{align} + where the Lagrangian is + \begin{align} + \mathcal{L}(g_{\mu\nu}, Y_\mu) = + 4\mathcal{L}_M(g_{\mu\nu})+ + \mathcal{L}_Y(Y_\mu)+ + \mathcal{L}_\phi(g_{\mu\nu}, d) + \end{align} + here the $d$ in $\mathcal{L}_\phi$ is from $D_F$ in equation + \ref{dirac}. The Lagrangian $\mathcal{L}_M$ is like in equation + \ref{lagr}. The Lagrangian $\mathcal{L}_Y$ is the kinetic term of the + $U(1)$ gauge field $Y_\mu$ + \begin{align} + \mathcal{L}_Y(Y_\mu):= \frac{f(0)}{6\pi^2} + Y_{\mu\nu}Y^{\mu\nu}\;\;\;\;\;\;\;\;\text{with}\;\;\; Y_{\mu\nu} = + \partial_\mu Y_\nu - + \partial_\nu Y_\mu. + \end{align} + Then there is $\mathcal{L}_\phi$, which has two constant terms + (disregarding the boundary term) that add up to the Cosmological Constant + and a term that for the Einstein-Hilbert action + \begin{align} + \mathcal{L}_\phi(g_{\mu\nu}, d) := \frac{2f_2 \Lambda ^2}{\pi^2} + |d|^2 + \frac{f(0)}{2\pi^2} |d|^4 + \frac{f(0)}{12\pi ^2} s |d|^2. + \end{align} +\end{proposition} +\begin{proof} + The Trace of $\mathbb{C}^4$ (the Hilbertspace) gives $N=4$. With $B_\mu$ + like in equation \ref{field} we have $\text{Tr}(F_{\mu\nu} + F^{\mu\nu})=4Y_{\mu\nu}Y^{\mu\nu}$. This provides $\mathcal{L}_Y$. + Furthermore we have $\Phi^2 = D_F^2 = |d|^2$ and $\mathcal{L}_\phi$ only + give numerical contributions to the cosmological constant and the + Einstein-Hilbert action. + + The proof is relying itself on just plugging the terms into the previous + proposition, for which I didn't write the proof for. +\end{proof} \end{document}