Per Vognsen

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Name	Per Vognsen
Member for	3 years
Seen	Mar 17 at 1:38
Website	mathoverflow.net/users/2036
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Age	30

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6

Questions

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19

25

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1

answer

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Geometric interpretation of characteristic polynomial

linear-algebra matrices traces

jul 29 10 at 2:48 Per Vognsen 1,041●5●15

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15

votes

2

answers

1k

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When is a symplectic manifold equivalent to a cotangent bundle?

sg.symplectic-geometry differential-topology mp.mathematical-physics

aug 20 10 at 22:16 Will Merry 343●1●4●8

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10

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answer

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Conceptual explanation of Strassen’s trick for matrix multiplication

algorithms noncommutative-rings

sep 24 at 5:37 Denis Serre 18.7k●1●31●93

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8

votes

1

answer

630

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Cubical cohomology and de Rham cohomology

at.algebraic-topology ag.algebraic-geometry dg.differential-geometry hodge-theory

jul 28 10 at 9:06 Peter Arndt 6,868●18●42

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6

votes

2

answers

811

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Bijective proof of weak form of Stirling’s approximation

co.combinatorics computer-science

aug 2 10 at 8:45 Igor Pak 8,206●2●17●57

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5

votes

2

answers

613

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Proving equality of varieties by dimension counting

linear-algebra ag.algebraic-geometry

aug 1 10 at 16:04 Francesco Polizzi 18.8k●2●34●55

21

Answers

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Thinking and Explaining

Jokes in the sense of Littlewood: examples?

eBook readers for mathematics

How can I visualize the nontrivial element of $\pi_4(S^3)$ and $\pi_5(S^3)$ ?

Why linear algebra is fun!(or ?) (2)

Are there other nice math books close to the style of Tristan Needham?

Deformations and the dual numbers

Intuitive Proof of Cramer’s Decomposition Theorem

Reference request: an elementary proof of Brouwer fixed-point theorem.

Laplacian operator and relation to the Laplace Transform

Book on Symplectic Geometry

What happens when we print the digits of a real number?

Projective transformation between polygons.

Applications and Natural Occurrences of Prime Numbers

Multivariate Bisection

“Convex Optimization” over varying-dimension vector space?

Do convolution and multiplication satisfy any nontrivial algebraic identities?

Learning Topology

A generalization of Boolean matrix multiplication for order-3 tensors

How to prove that a set of facets are all the facets of a convex polytope.

What is a reasonable finitary analogue of the statement that harmonic functions are smooth?

68

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traces

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geometry
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