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Top Questions
10 votes

What is the convex hull of the quaternionic symmetries of the 3 dimensional cube?

convex-polytopes quaternionic-geometry asked Jan 27, 2020 at 13:09
mathoverflow.net

9 votes

Do extensions of pure states separate points?

c-star-algebras amenability asked Oct 9, 2021 at 19:30
mathoverflow.net

9 votes

Does left-multiplication by compact operators turn strong-convergence into norm-convergence?

functional-analysis compact-operators strong-convergence asked Dec 4, 2020 at 23:23
math.stackexchange.com

8 votes

If the diagonal of a positive operator is compact, is the operator itself compact?

fa.functional-analysis oa.operator-algebras operator-theory asked Mar 18, 2017 at 21:07
mathoverflow.net

8 votes

"cl-flet" macro not allowing for recursive functions

elisp-macros flet asked Oct 30, 2017 at 11:30
emacs.stackexchange.com

7 votes

Using case to compare with a variable

conditionals asked Oct 26, 2017 at 19:27
emacs.stackexchange.com

7 votes

What is the most efficient way to open glass curtains

combinatorial-optimizatio asked Aug 23, 2016 at 17:38
mathoverflow.net

7 votes

Generalizing C*-algebraic results to purely algebraic situations

ra.rings-and-algebras c-star-algebras asked Aug 25, 2016 at 15:01
mathoverflow.net

7 votes

How to make sure no global variables have been created in a piece of lisp code?

local-variables let-binding lexical-binding asked Feb 12, 2021 at 15:38
emacs.stackexchange.com

7 votes

Is every sequentially $\sigma(E',E)$-continuous linear functional on a dual Banach space $E'$ necessarily a point evaluation?

fa.functional-analysis operator-theory duality asked Jan 10, 2021 at 18:09
mathoverflow.net

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Top Answers
63
Short exact sequences every mathematician should know
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Basis-free, field-independent definition of determinants?
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Emacs Org-mode - Export to another directory?
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Intuition behind Pontryagin duality
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12
Do unique $n^{th}$ roots commute in groups?
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12
Non-commutative duality I: Which C*-algebras are (isomorphic to a) convolution algebra?
mathoverflow.net

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Basic Confusion on Push-Forward of a Measure
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9
How can I reconcile cardinality and and subsets in Set Theory?
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8
Convergence of $\sum_{n}\frac{q_n}{n}$, where $(q_n)$ enumerates $\mathbb{Q}\cap[0,1]$?
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8
Does left-multiplication by compact operators turn strong-convergence into norm-convergence?
math.stackexchange.com

7
An example which disproves $\|p(T)\|_{op} = \|p\|_\sup$ in arbitrary Banach spaces (Gelfand theory).
math.stackexchange.com

7
Natural map $C^*(G) \to M(A\rtimes G)$
mathoverflow.net

7
Relation between maximal and reduced group $C^*$-algebras
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7
Characterisation of finite dimensional C*-algebras?
mathoverflow.net

7
If an element in a Banach algebra is anihilated by an analytic function then it must be algebraic.
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Uniqueness of marginal measures
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Characterization of Hilbert spaces using orthogonal decomposition
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If a linear non bounded closed operator in Hilbert space has a real spectrum, is it self-adjoint?
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6
Is the space of distinct pairs of points in a circle homeomorphic to a product?
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6
Is $\text{GL}_2(\mathbb{R})/\mathbb{R}^{\times}$ isomorphic to $\text{SL}_2(\mathbb{R})$?
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6
Example of an ergodic transformation with some properties in the spectrum of the Koopman operator
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Definition of 'product states' for $C^*$-algebras
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Closed subspace consisting of continuous functions in $L^{2}([0,1])$ is finite-dimensional
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Convergence of formal power series
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dense subspace of $L^2$ that is disjoint to $L^p$
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Deciding eigenvalue degeneracy without calculating all eigenvalues and eigenvectors
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Is a real matrix that is both normal and diagonalizable symmetric? If so, is there a proof of this not using the spectral theorem?
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5
Given a set of unitary matrices, can one find a vector whose images under these unitary matrices span the underlying Hilbert space?
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5
Intuition behind multiplicative unitaries
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What do weak-star limits of normal states on von Neumann algebras look like?
math.stackexchange.com

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