# All Questions

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### Hypergraph clustering conductance Formula

Consider the Hypergraph $H=(V,E)$, with $V$ being the vertices and $E$ being the hyperedges. What is the formula of conductance $\Phi(S)$ for hypergraphs, with $S$ being a set of vertices (cluster ...
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### On the notion of conelike stratified (cs-) space

The notion of cs-stratification of a topological space is apparently due to Siebenmann, see also the paper by N. Habegger and L. Saper in the paper "Intersection cohomology of cs-spaces and Zeeman's ...
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Let $p:Y=\mathbb P(\mathcal E_3^{\vee})\rightarrow G(3,n+1)$ be the universal family of hyperplanes (i.e. lines) of the planes of $\mathbb P^{n}$. The following isomorphism seems natural $$\mathcal O_{... 3answers 144 views ### For which finite groups G does the Wedderburn decomposition of \mathbb{Q}[G] consist only of fields and division algebras? Let G be a finite group. Then the rational group algebra \mathbb{Q}[G] has a wedderburn decomposition of the form \prod_i M_{n_i}(D_i) where each D_i is a division algebra. My question is: ... 0answers 47 views ### Applications of group [on hold] I have heard that Group ( i.e a non empty set defined by a binary operation satisfying closure,associative,identity,inverse axioms ) are applied in the usage of credit cards. How is that used exactly ?... 1answer 77 views ### Examples of canonical bases Let A=(a_{ij}) be a generalized Cartan matrix of order n and D=diag(d_1,\ldots,d_n) the diagonal matrix such that DA is symmetric. Let$$E_{ij}=\sum_{r+s=1-a_{ij}} (-1)^r E_i^{(r)} E_j E_i^{(s)...
Consider a standard statistical estimation problem with iid real observations $\{X_i\}_{i=1}^N$. For a collection of real functions $\mathcal{F}$, I want to get an estimate of the uniform rate of ...