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What are the matrix coefficients associated with the irreducible representations of compact real linear algebraic groups?

What are the matrix coefficients associated with the irreducible representations of a compact real linear algebraic group $G$? Peter-Weyl tells us that $L^2(G)$ is the (closure of) $\bigoplus_\pi A_{\...
Andrew NC's user avatar
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3 votes
0 answers
168 views

Efficient integration over part of a compact group

I am trying to find the matrix coefficients $\{\hat{c}^{\alpha}_{i j}\}$ that minimize the mean squared error against a function $f(g)$ over a compact group to some bandwidth cutoff $\ell$. $$\...
Nick's user avatar
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2 votes
0 answers
118 views

What are the finite-dimensional irreducible unitary representations of $E(3)$?

Let $E(3)$ be the Euclidean group of $\mathbb{R}^3$ defined, e.g., by $$E(3)=SO(3)\ltimes T(3)$$ where $T(3)$ is the translation group. I am looking for a reference classifying all the finite-...
PontyMython's user avatar
1 vote
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Exploring Plancherel measure decay rates linked to a specific $AD(\Gamma)$ range

In this paper on the amenability constant of Fourier algebras Theorem 1.5 presents a formula connecting $AD(\Gamma)$, the anti-diagonal constant of a countable virtually abelian group $\Gamma$, to ...
AmateurMathematician's user avatar
1 vote
0 answers
297 views

Intersection of thickly syndetic sets

Question: Let $\Gamma$ be a countable group. Is the intersection of two thickly syndetic sets still thickly syndetic? I've only seen the proof for the group $\mathbb{Z}$ (and I believe this method ...
ARG's user avatar
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1 vote
0 answers
311 views

Show that $\mathrm{SL}_2(\mathbb{F}_p)$ is quasi-random

Terry Tao gives this oblique definition of quasirandom group in his notes 3 $G$ is quasi-random (of order $D$) if all non-trivial unitary representations $\rho: G \to U(H)$ have dimension at least $...
john mangual's user avatar
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