Stack Exchange

Mikhail Ostrovskii

New York, United States

http://facpub.stjohns.edu/ostrovsm/

I think that MathOverflow is a very interesting and useful web site. I try to answer those questions which I can answer without devoting to this significant time (exceptions are given to those questions which I consider as interesting research problems, alas, no success so far).

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Top Questions
31 votes

Isometric embeddings of finite subsets of $\ell_2$ into infinite-dimensional Banach spaces

mg.metric-geometry banach-spaces metric-embeddings asked Oct 18 '15 at 0:44
mathoverflow.net

29 votes

Do there exist infinite-dimensional Banach spaces in which every bounded linear operator attains its norm?

fa.functional-analysis banach-spaces operator-theory norms operator-norms asked Feb 27 '16 at 18:53
mathoverflow.net

17 votes

Large almost equilateral sets in finite-dimensional Banach spaces

fa.functional-analysis mg.metric-geometry banach-spaces discrete-geometry metric-embeddings asked Nov 26 '14 at 18:15
mathoverflow.net

16 votes

Generalizing the Mazur-Ulam theorem to convex sets with empty interior in Banach spaces

mg.metric-geometry banach-spaces group-actions asked Dec 8 '15 at 17:55
mathoverflow.net

12 votes

Is $\ell_p$ $(1<p<\infty)$ finitely isometrically distortable?

fa.functional-analysis mg.metric-geometry banach-spaces metric-spaces metric-embeddings asked Dec 27 '15 at 9:03
mathoverflow.net

11 votes

Embeddings of finitely generated groups into uniformly convex Banach spaces

gr.group-theory mg.metric-geometry banach-spaces geometric-group-theory metric-embeddings asked Aug 19 '14 at 22:11
mathoverflow.net

10 votes

The number of relevant scales for a finite metric space

co.combinatorics graph-theory mg.metric-geometry asked Jul 27 '13 at 19:49
mathoverflow.net

6 votes

Large subspaces with small basic constants in finite-dimensional Banach spaces

banach-spaces asked Jul 26 '14 at 18:46
mathoverflow.net

6 votes

Embedding of real trees into $\ell_1(\Gamma)$

reference-request fa.functional-analysis mg.metric-geometry banach-spaces trees asked Dec 14 '15 at 4:04
mathoverflow.net

5 votes

On optimal dual solutions for the minimum weight perfect matching problems in the case of metric weights

linear-programming combinatorial-optimization matching-theory perfect-matchings asked May 27 '19 at 0:23
mathoverflow.net


Top Answers
23
Who proved that $l^1$ and $L^1[0,1]$ are not isomorphic?
mathoverflow.net

10
Two questions about basic sequences
mathoverflow.net

10
Complemented subspaces constructed from finite pieces- part II
mathoverflow.net

10
In infinite dimensions, is it possible that convergence of distances to a sequence always implies convergence of that sequence?
mathoverflow.net

9
Well-complemented copies of $\ell_p^n$
mathoverflow.net

8
If a subspace $F$ is contained in a subspace $G$, and $H$ is close to $G$, can we choose a subspace of $H$ close to $F$?
mathoverflow.net

7
Almost isometric embeddability implies isometric embeddability
mathoverflow.net

7
Is X+X finitely representable in X?
mathoverflow.net

6
Location of a Banach Space inside its bidual
mathoverflow.net

6
Thin large subspaces of $\ell^N_1$
mathoverflow.net

6
Banach spaces $X$ with $\ell_2(X)$ not isomorphic to $L_2([0,1],X)$
mathoverflow.net

6
Antiproximanal subspace of $L_1[0,1]$
mathoverflow.net

5
ODE properties true in finite dimension but not in Banach spaces of infinite dimension
mathoverflow.net

5
Basis equivalent with a monotone basis
mathoverflow.net

5
Under what conditions can we put a complete norm on a linear subspace of a separable Banach space?
mathoverflow.net

5
If $E\oplus_\phi E \cong E\oplus_\psi E,$ does it imply that $\phi= \psi$?
mathoverflow.net

5
Characterization of operator ranges
mathoverflow.net

5
Existence of a Hölder-free space
mathoverflow.net

5
Approximation property of a Banach space in terms of finite-rank projections
mathoverflow.net