MathOverflow

Math Overflow. Q&A for professional mathematicians.

Read Mathoverflow.net news digest here: view the latest Math Overflow articles and content updates right away or get to their most visited pages. Mathoverflow.net belongs to a group of fairly successful websites, with more than 458K visitors from all over the world monthly. It seems that Math Overflow content is notably popular in USA, as 32.4% of all users (148K visits per month) come from this country. We haven’t detected security issues or inappropriate content on Mathoverflow.net and thus you can safely use it. Mathoverflow.net is hosted with Stack Exchange, Inc. (United States) and its basic language is English.

  • Content verdict: Safe
  • Website availability: Live
  • English language flagLanguage: English
  • Last check:
  • 15 260

    Visitors daily
  • 54 936

    Pageviews daily
  • 6

    Google PR
  • 20 139

    Alexa rank

Mathoverflow.net news digest

  • 12 years

    Diophantine equation - $a^4+b^4=c^4+d^4$ ($a,b,c,d > 0$)

    How can I find the general solution of $a^4+b^4=c^4+d^4$ ($a,b,c,d > 0$)?And how did Euler find the solution $158^4+59^4=133^4+134^4$?

  • 0 days

    Can fractal sets be almost closed under addition?

    Let $E \subset \mathbb R^n$ have nonzero finite $s$-dimensional Hausdorff measure. Consider the natural uniform probability measure on $E$, which is just normalised $s$-Hausdorff measure.
    Question: Let $X, Y$ be drawn uniformly and independently from $E$. Is it true there exists a constant $\delta(s, n) > 0$ independent of $E$ such that...

  • 2 years

    Distribution of the change in Hamming distance between two sequences

    Suppose I have two strings $s_1$ and $s_2$ of equal length $L$ with an alphabet size of $k \geq 2$. Suppose further that these two strings initially have a Hamming distance equal to $d_0 = H(s_1,s_2)$.
    I then proceed through each character in one of the strings (say $s_2$), changing with probability $\mu$ the character to another distinct value in the alphabet, uniformly from the $k-1$ choices remaining. The number of edits is therefore distributed...

  • 0 days

    Sparse divisor/Kloosterman sums over divisors of h 6 +27k 2 in a no-long-variabl...

    I am trying to understand whether there is any existing machinery that could plausibly give cancellation in the following sparse divisor/Kloosterman-type regime.
    Let
    $$R(h)=h^6+27k^2,$$

Domain history

Web host: Stack Exchange, Inc.
Registrar: GoDaddy.com, LLC
Registrant: Registration Private (Domains By Proxy, LLC)
Updated: July 07, 2025
Expires: July 14, 2026
Created: July 14, 2009

Whois record

Visitor gender

Male

Female

Safety scores

Trustworthiness

Excellent

Child safety

Excellent