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Sergei Ivanov's user avatar
Sergei Ivanov's user avatar
Sergei Ivanov's user avatar
Sergei Ivanov
  • Member for 13 years, 7 months
  • Last seen more than a month ago
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I am a research fellow at St.Petersburg Department of Steklov Math Institute
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All Questions Answers
Score Newest
answer
121
solving $f(f(x))=g(x)$
Mar 9, 2010
answer
103
Is the sphere the only surface with circular projections? Or: Can we deduce a spherical Earth by observing that its shadows on the Moon are circular?
Sep 17, 2010
answer
69
How to solve $f(f(x)) = \cos(x)$?
Mar 9, 2010
answer
64
Smoothness of distance function in Riemannian Manifolds
Apr 14, 2010
answer
62
Is there a dense subset of the real plane with all pairwise distances rational?
Mar 23, 2010
question
58
How do they verify a verifier of formalized proofs?
Mar 16, 2010
answer
45
Is every closed set of Q² the intersection of some connected closed set of R² with Q²
Nov 16, 2010
answer
43
Why are free groups residually finite?
Apr 6, 2010
answer
40
When factors may be cancelled in homeomorphic products?
May 30, 2010
answer
38
An easy proof that $S(n)$ does not embed into $A(n+1)$?
May 16, 2011

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