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 CloudFlare, Inc. (United States) and its basic language is English.
Content verdict: Safe
Website availability: Live
Language: English
Last check:
-
15 260
Visitors daily -
54 936
Pageviews daily -
6
Google PR -
23 455
Alexa rank
Best pages on Mathoverflow.net
-
Q&A for professional mathematicians
-
Let $A$ be a $C^*$-algebra and $(a_{ij}) \in M_n(A)$ be a positive matrix. Does there exist a constant $C \ge 0$ (not depending on the $a_{ij}$) such that $$\lVert(a_{ij})\rVert \le C \Bigl\lVert\s...
-
Hottest Questions Today - MathOverflow
Skip to main content Stack Exchange Network Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, ...
Mathoverflow.net news digest
-
0 days
Homeomorphisms of Minkowski space
I was reading the paper “On two topologies that were suggested by Zeeman” by Papadopoulos and Papadopoulos. In Theorem 1.1, the authors show that the group of homeomorphisms of Minkowski space coincides with the group of automorphisms of this space.
In light of this result, is it possible to define a topology on a manifold such that a transformation group acting on it is exactly the same as its homeomorphism group?... -
0 days
Irreducibility of a polynomial through Newton polygon or residual reduction
Let $K=\mathbb{Q}_3(t)$ be the finite extension of the $3$-adic number field $\mathbb{Q}_3$, where $t=3^{1/13}$. I want to know if the polynomial $$f(x)=(x^9-t^2)^3-3^4x+3^3t^5 \in K[x]$$ reducible or not.
Method 1: If $v_3$ is the normalized valuation $v_3(3)=1$, then $v_3(t)=\frac{1}{13}$ as $t^{13}=3$. Let us find the Newton polygon, whose vertices are $(27,0), (28, 15/13), (9, 17/13), (1,4), (0, 6/13)$ .... -
11 years
Counting perfect matchings with integrals
Has anyone used the Joni-Rota-Godsil integral formula (see details below) to count perfect matchings of square-grid graphs, Aztec diamond graphs, hexagon-honeycomb graphs, etc.? (Or even just to count perfect matchings of the 2-by-$n$ grid?)
I suspect that the answer is "no", since the method seems to implicitly involve the whole matching polynomial (instead of restricting to perfect matchings), and I don't think that the matching polynomials of these graphs are particularly tractable (though... -
0 days
Classifying the nature of idempotents on finite groups
Let $A = \ell^1(G)$ be the convolution Banach $*$-algebra of a finite (not necessarily abelian) group $G$ with norm $\|\cdot\|_1$,let $\mu \in A$ be a probability measure, and set $\delta = \|\mu * \mu - \mu\|_1 \leq 1/10$.Is it the case that there must...
Domain history
| Web host: | CloudFlare, 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
ExcellentChild safety
Excellent
