From 325d12ba7e2b9cecd50b1d58e06b8de66b8b3a20 Mon Sep 17 00:00:00 2001 From: prescientmoon <git@moonythm.dev> Date: Thu, 20 Mar 2025 17:06:00 +0100 Subject: [PATCH] Remove matroid thingy --- main.tex | 73 +++++++++++++++++++++++++------------------------------- 1 file changed, 32 insertions(+), 41 deletions(-) diff --git a/main.tex b/main.tex index aa16097..ffadfd8 100644 --- a/main.tex +++ b/main.tex @@ -75,16 +75,7 @@ code-for-last-col = \color{blue} \end{enumerate} \end{frame} -% should we make is so that these bullet points appear one after another? Yes -\begin{frame}{Abstracting Independence - Motivation} - \begin{itemize} - \item 1 - \item 2 - \end{itemize} -\end{frame} - \include{prerequisites} - \include{isospectral} \begin{frame}[fragile]{CMB Anisotropy of Homogeneous Spherical Spaces} @@ -92,9 +83,9 @@ code-for-last-col = \color{blue} \item Manifolds $\textcolor{blue}{M} := \mathbb{S}^3 /_ \sim$ where $\sim $ identifies the orbits of finite $H \leq SO(4)$ \item Helmholtz equation on $\textcolor{blue}{M}$ given by - \begin{align*} - (\Delta + E_{\textcolor{red}{\beta}}^{\textcolor{blue}{M}})\psi_{\textcolor{red}{\beta}}^{{\textcolor{blue}{M}}, i} = 0 - \end{align*} + \begin{align*} + (\Delta + E_{\textcolor{red}{\beta}}^{\textcolor{blue}{M}})\psi_{\textcolor{red}{\beta}}^{{\textcolor{blue}{M}}, i} = 0 + \end{align*} \item In fact $E_{\textcolor{red}{\beta}}^m = {\textcolor{red}{\beta}}^2-1$ for $\textcolor{red}{\beta} \in \mathbb{N}$ we call $\textcolor{red}{\beta}$ a wave number @@ -138,15 +129,15 @@ code-for-last-col = \color{blue} \begin{frame}{CMB radiation in an inhomogeneous spherical space} \begin{itemize} - \item Manifolds of the form $\mathbb S/\Gamma$ with $\Gamma$ a group acting on $\mathbb S^3$. + \item Manifolds of the form $\mathbb S/\Gamma$ with $\Gamma$ a group acting on $\mathbb S^3$. \item Multi-connected space: it has non-contractable loops \item Inhomogeneous space: it does not look identical from every point in space \item Fixing $|\Gamma|=8$, we have three multi-connected manifolds, up to equivalence: - \begin{enumerate} - \item homogeneous: $N3$ and $L(8,1)$ - \item inhomogeneous: $N2 \equiv L(8,3)$ - \end{enumerate} - \item Results: inhomogeneous spaces have more variety in CMB anisotropies than homogeneous spaces, because observer dependency changes the suppression of CMB anisotropies. + \begin{enumerate} + \item homogeneous: $N3$ and $L(8,1)$ + \item inhomogeneous: $N2 \equiv L(8,3)$ + \end{enumerate} + \item Results: inhomogeneous spaces have more variety in CMB anisotropies than homogeneous spaces, because observer dependency changes the suppression of CMB anisotropies. \end{itemize} @@ -155,34 +146,34 @@ code-for-last-col = \color{blue} \section{Test for anisotropy in the mean of the CMB temperature fluctuation in spherical harmonic space} \begin{frame}{The setup} - From the perspective of an Earth-based observer, we can view CMB as a function defined on the celestial sphere $\mathbb{S}^2$. \\ - So, $\Delta T(\hat{n})$ expanded using \textit{spherical harmonics}, with $a_{\ell m}$ its coefficients.\\ - We assume the fluctuations: - \begin{itemize} - \item Statistically isotropic and homogeneous in the mean. - \item Gaussian distribution. - \item $\textcolor{blue}{a_{\ell m}}$ are independent Gaussian variables. - \end{itemize} - Coefficients should satisfy:$\langle \textcolor{blue}{a_{\ell m}} \rangle = 0$ \\ + From the perspective of an Earth-based observer, we can view CMB as a function defined on the celestial sphere $\mathbb{S}^2$. \\ + So, $\Delta T(\hat{n})$ expanded using \textit{spherical harmonics}, with $a_{\ell m}$ its coefficients.\\ + We assume the fluctuations: + \begin{itemize} + \item Statistically isotropic and homogeneous in the mean. + \item Gaussian distribution. + \item $\textcolor{blue}{a_{\ell m}}$ are independent Gaussian variables. + \end{itemize} + Coefficients should satisfy:$\langle \textcolor{blue}{a_{\ell m}} \rangle = 0$ \\ - \textbf{\textcolor{red}{Remark:}} $\langle \textcolor{blue}{a_{\ell m}} \rangle \neq 0$, \textbf{suggests possible anisotropies or preferred directions in the universe} + \textbf{\textcolor{red}{Remark:}} $\langle \textcolor{blue}{a_{\ell m}} \rangle \neq 0$, \textbf{suggests possible anisotropies or preferred directions in the universe} \end{frame} \begin{frame}{The setup} -Real CMB observations are affected by instrumental noise and \textit{sky masking}. So, estimating $C_\ell$ accurately requires simulations. + Real CMB observations are affected by instrumental noise and \textit{sky masking}. So, estimating $C_\ell$ accurately requires simulations. -Given $C^{th}_\ell$, used to generate synthetic realizations of the CMB sky -\[ - \textcolor{blue}{a_{\ell m}} \sim \mathcal{N} (0, C_\ell^{\text{th}}). -\] -However, this introduces bias, which must be corrected using a decorrelation matrix $W$, and a \textit{sky mask} matrix $M$ which accounts for issues caused by masking effects. + Given $C^{th}_\ell$, used to generate synthetic realizations of the CMB sky + \[ + \textcolor{blue}{a_{\ell m}} \sim \mathcal{N} (0, C_\ell^{\text{th}}). + \] + However, this introduces bias, which must be corrected using a decorrelation matrix $W$, and a \textit{sky mask} matrix $M$ which accounts for issues caused by masking effects. -Giving us the test statistic (tests the assumption of statistical isotropy): -\[ - S_i = \sum_{j} W_{ij} M_j, -\] -Which examines $\langle \textcolor{blue}{a_{\ell m}} \rangle$ across multipole ranges. \\ -\textbf{\textcolor{red}{Recall:}} $\langle a_{\ell m} \rangle \neq 0$, \textbf{suggests possible anisotropies or preferred directions in the universe} + Giving us the test statistic (tests the assumption of statistical isotropy): + \[ + S_i = \sum_{j} W_{ij} M_j, + \] + Which examines $\langle \textcolor{blue}{a_{\ell m}} \rangle$ across multipole ranges. \\ + \textbf{\textcolor{red}{Recall:}} $\langle a_{\ell m} \rangle \neq 0$, \textbf{suggests possible anisotropies or preferred directions in the universe} \end{frame} @@ -192,7 +183,7 @@ Which examines $\langle \textcolor{blue}{a_{\ell m}} \rangle$ across multipole r \includegraphics[width=0.7\linewidth]{DSE-Test Graph} \caption{The decorrelated band mean spectrum obtained by the seven-year WMAP data [9].} \end{figure} -\textcolor{red}{Remark}In a positively curved space certain multipoles scales being preferred or suppressed in the CMB power spectrum. + \textcolor{red}{Remark}In a positively curved space certain multipoles scales being preferred or suppressed in the CMB power spectrum. \end{frame}