Denis Serre's user avatar
Denis Serre's user avatar
Denis Serre's user avatar
Denis Serre
  • Member for 13 years, 7 months
  • Last seen this week
130 votes

Why were matrix determinants once such a big deal?

124 votes

Not especially famous, long-open problems which anyone can understand

58 votes
Accepted

Is square of Delta function defined somewhere?

50 votes

Is the boundary $\partial S$ analogous to a derivative?

48 votes

Why are matrices ubiquitous but hypermatrices rare?

38 votes

Old books still used

36 votes

Examples of common false beliefs in mathematics

35 votes
Accepted

how to find/define eigenvectors as a continuous function of matrix?

31 votes

German mathematical terms like "Nullstellensatz"

29 votes
Accepted

2D problems which are easier to solve in 3D

29 votes
Accepted

Kind of submultiplicativity of the Frobenius norm: $\|AB\|_F \leq \|A\|_2\|B\|_F$?

28 votes

Mathematical "urban legends"

28 votes

Awfully sophisticated proof for simple facts

27 votes

How often do people read the work that they cite?

27 votes

John Nash's Mathematical Legacy

26 votes

A sum involving derivatives of Vandermonde

25 votes

The half-life of a theorem, or Arnold's principle at work

24 votes

Where is number theory used in the rest of mathematics?

24 votes
Accepted

Strange behavior of $x_{n+1}=x_n +\lambda \sin x_n$

23 votes
Accepted

Self-dual normed spaces which are not Hilbert spaces

22 votes

The statement that $A \ge B$ implies $A^{-1} \le B^{-1}$ is still true for matrices?

21 votes

Is it possible to start a PhD in mathematics at the age of 29?

21 votes
Accepted

Is the Mendeleev table explained in quantum mechanics?

21 votes

Facts from algebraic geometry that are useful to non-algebraic geometers

20 votes
Accepted

Find the determinant of a matrix given the determinant of all $p\times p$ sub-matrices?

20 votes

Results in linear algebra that depend on the choice of field

20 votes

Have you solved problems in your sleep?

19 votes

Is the determinant the only multiplicative matrix function?

19 votes

Examples of unexpected mathematical images

19 votes
Accepted

Non real eigenvalues for elliptic equations

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