Revival - Badge - Mathematics Stack Exchange

Revival

Answer more than 30 days after a question was asked as first answer scoring 2 or more. This badge can be awarded multiple times.

Awarded 23076 times.

Apps for practicing math (all levels)

Awarded Nov 15 at 10:00

Some Guy

2,7483 gold badges17 silver badges33 bronze badges

Continuation of the “Lorenzified” Riemann zeta $\zeta_{L}(x)$?

Awarded Nov 14 at 18:53

Sangchul Lee

186k17 gold badges302 silver badges500 bronze badges

Geometric proof/evidence for the 3x3 matrix determinant's formula?

Awarded Nov 14 at 18:53

mndtr

931 silver badge6 bronze badges

Ideals of the upper-triangular matrix algebra $\mathcal{T}_n$ over $\Bbb{R}$ or $\Bbb{C}$

Awarded Nov 14 at 11:04

Julian Kuelshammer

9,7904 gold badges41 silver badges88 bronze badges

How can I write $2+5i$ in polar form?

Awarded Nov 14 at 11:04

EM4

1,2772 gold badges11 silver badges25 bronze badges

An estimate of the uniformly-localized $L^p$ norm

Awarded Nov 14 at 11:04

Rayyyyy

1599 bronze badges

Prove that $\chi(X \times Y)=\chi(X)\,\chi(Y) $ for finite CW complexes

Awarded Nov 14 at 2:57

Ashani

5644 silver badges12 bronze badges

Estimating the Twin prime constant

Awarded Nov 13 at 18:32

Klangen

5,5295 gold badges40 silver badges77 bronze badges

Integration of $\int_0^{\infty} \frac{\ln\left(x+\frac{1}{x}\right)}{1+x^2}~dx$

Awarded Nov 13 at 9:26

Lai

33.2k4 gold badges22 silver badges82 bronze badges

group von Neumann algebra and its Plancherel weight

Awarded Nov 12 at 18:34

Mogget

8554 silver badges11 bronze badges

Existence of a Linear Recurrence Modulo $p$ with Period $p^2 - 1$

Awarded Nov 12 at 16:08

David E Speyer

65k7 gold badges197 silver badges300 bronze badges

if $A\subseteq B$ are subsets of a group $G$, then $C_G(B)$ is a subgroup of $C_G(A)$

Awarded Nov 12 at 15:21

Kevin Chen

1662 silver badges13 bronze badges

Are division algebras over local fields compact mod center?

Awarded Nov 12 at 4:41

leoli1

8,9081 gold badge14 silver badges39 bronze badges

Slot size bound for chaining

Awarded Nov 11 at 21:36

Yola

2,1932 gold badges20 silver badges35 bronze badges

Hydrostatic force on a dam

Awarded Nov 11 at 19:48

Dr. Z

213 bronze badges

Fundamental theorem of calculus of Banach-space valued functions

Awarded Nov 11 at 14:23

trucupey

714 bronze badges

Classification of normal forms of relations on vector spaces

Awarded Nov 11 at 9:22

Vladimir Lysikov

5,4502 gold badges21 silver badges35 bronze badges

Interpreting Doob's Up-Crossing Inequality

Awarded Nov 11 at 2:48

Tanizaki

4512 silver badges9 bronze badges

Border rank of tensors

Awarded Nov 10 at 6:22

Fritz Hefter

17310 bronze badges

Is there a simple conceptual proof of Poisson summation formula analogous to the inavariance of trace under basis change?

Awarded Nov 9 at 19:01

nesqwa

4715 bronze badges

integral inequality involving $\sup|f'|$

Awarded Nov 9 at 6:21

T﹏T

3,4781 gold badge3 silver badges34 bronze badges

Is there a closed-form expression for the sum of the first k terms in a binomial series?

Awarded Nov 8 at 19:41

LSA

4223 silver badges12 bronze badges

Homology groups of orientable surfaces.

Awarded Nov 8 at 17:41

Eric Wofsey

344k28 gold badges487 silver badges705 bronze badges

How to find area of a polygon built on the roots of a given polynomial?

Awarded Nov 8 at 8:40

Eli Seamans

6424 silver badges11 bronze badges

Chess tournament problem

Awarded Nov 7 at 18:17

Joffan

40.6k5 gold badges53 silver badges89 bronze badges

Question about weight 2 Eisenstein series

Awarded Nov 7 at 17:27

Ziqian Xie

1,12310 silver badges21 bronze badges

Quadruple Integral $\int_0^1\int_0^1\int_0^1\int_0^1\sqrt{x^{\overset{\,}{2}}+y^2+z^2+w^2}{\kern 2pt}{\rm\,d}x{\rm\,d}y{\rm\,d}z{\rm\,d}w$

Awarded Nov 7 at 8:32

user170231

27.1k3 gold badges49 silver badges96 bronze badges

Asymptotic behavior of $L^2$ norm for increased matrix dimensions

Awarded Nov 7 at 0:40

138 Aspen

1,3575 silver badges31 bronze badges

Principal and Vector bundles over stacks

Awarded Nov 6 at 20:38

Adittya Chaudhuri

5193 silver badges12 bronze badges

How would you integrate $\sin(1/x)$?

Awarded Nov 6 at 20:38

Тyma Gaidash

13.9k4 gold badges31 silver badges88 bronze badges

If $a+b+c+d+e=0$ so $180(a^6+b^6+c^6+d^6+e^6)\geq11(a^2+b^2+c^2+d^2+e^2)^3$

Awarded Nov 5 at 21:30

River Li

51.4k3 gold badges46 silver badges145 bronze badges

Exponential distribution unbiased estimator

Awarded Nov 5 at 17:02

Henry

172k10 gold badges139 silver badges299 bronze badges

Maximal almost disjoint family not countable

Awarded Nov 5 at 11:40

Jakobian

15.9k3 gold badges30 silver badges58 bronze badges

Transformation of Ito diffusion such that the diffusion coefficient becomes constant (Change of variables)

Awarded Nov 5 at 8:19

Thomas Kojar

7,4292 gold badges17 silver badges50 bronze badges

Does division by 0 really have anything to do with $\lim_{x \to 0} \frac{1}{x}$?

Awarded Nov 4 at 17:47

jjagmath

24.7k3 gold badges29 silver badges59 bronze badges

Clarification of a step in the proof that preserving p-points is iterable of Bartoszyński-Judah.

Awarded Nov 4 at 6:31

Juris Steprans

1463 bronze badges

Fourier transform of integral kernel of the free resolvent

Awarded Nov 4 at 5:45

138 Aspen

1,3575 silver badges31 bronze badges

A version of Van der Waerden's theorem

Awarded Nov 3 at 5:21

Racso

465 bronze badges

Problem 5D.4 Isaacs' Finite Group Theory

Awarded Nov 3 at 4:26

Steve D

6,0502 gold badges17 silver badges33 bronze badges

$a$ has no $p-$th root in $K$, then show that $X^{p^n}-a$ is irreducible in $K[x]$

Awarded Nov 2 at 19:51

user264745

4,6454 gold badges13 silver badges33 bronze badges

Show that $h$ is homotopic to the identity map relative to $C$.

Awarded Nov 2 at 4:42

Ryu

337 bronze badges

How to understand Artin-Rees lemma?

Awarded Nov 2 at 1:47

KReiser

76.3k16 gold badges66 silver badges120 bronze badges

A Question on Why Egorychev's Method Incorrectly Evaluates an Infinite Series

Awarded Nov 1 at 6:36

Vivek Kaushik

3,7341 gold badge27 silver badges34 bronze badges

Alternate Proof of Unique Lifting Property of Covering Spaces

Awarded Nov 1 at 5:17

Clapham

2231 silver badge7 bronze badges

What's the significance of the modulus in $\int \tan x \, dx \equiv \ln\lvert\sec x\rvert$?

Awarded Oct 31 at 4:10

David K

111k10 gold badges91 silver badges250 bronze badges

Maximal noncompact forms in classical Lie algebra?

Awarded Oct 30 at 23:02

Torsten Schoeneberg

30.9k2 gold badges60 silver badges114 bronze badges

Basic question about definition of Chern classes

Awarded Oct 30 at 19:33

Ben Steffan

10.8k5 gold badges20 silver badges58 bronze badges

Awarded Oct 30 at 17:01

Uskebasi

1,5911 gold badge9 silver badges20 bronze badges

Is there a geometrical proof for this locus (exterior of inner Steiner ellipse)?

Awarded Oct 30 at 9:53

Duong Ngo

2,9012 gold badges12 silver badges28 bronze badges

The geometry behind $\cos 48^{\circ}$ as decomposition of $\sin 18^{\circ}$

Awarded Oct 29 at 21:51

dfnu

8,5071 gold badge11 silver badges33 bronze badges

Subadditivity of Betti number for relative homology

Awarded Oct 29 at 21:51

Föölücks

4872 silver badges12 bronze badges

The linear group ${\rm SL}_n(\mathbb{F}_q)$ is absolutely irreducible

Awarded Oct 29 at 19:47

Jyrki Lahtonen

143k31 gold badges309 silver badges745 bronze badges

Local coordinates of one form on a principal bundle

Awarded Oct 29 at 18:21

nicrot000

1,5475 silver badges13 bronze badges

On a particular instance of the Baire category theorem

Awarded Oct 29 at 16:36

Tony

6,9831 gold badge35 silver badges60 bronze badges

Is there an error in the algebra of this GMAT problem explanation?

Awarded Oct 29 at 7:06

Sarvesh Ravichandran Iyer

78.4k9 gold badges88 silver badges162 bronze badges

Geometric intuition for limit of $\frac{1-\cos x}{x}$ as $x \to 0$

Awarded Oct 27 at 23:28

user

164k14 gold badges85 silver badges158 bronze badges

Prove Chain Rule with Newton's Approximation

Awarded Oct 26 at 14:54

SurfaceIntegral

4954 silver badges15 bronze badges

An algebraic space over etale topology is also a fppf-sheaf?

Awarded Oct 26 at 12:38

Tipping Octopus

1,6541 gold badge9 silver badges13 bronze badges

Nominal Rates/Effective rate computation, confusion.

Awarded Oct 26 at 11:22

alexjo

15.4k25 silver badges44 bronze badges

Define $\neg\phi$, $\phi\lor\psi$ and $\phi\land\psi$ using only $\rightarrow$ and $\bot$

Awarded Oct 26 at 5:02

Tankut Beygu

4,9262 gold badges13 silver badges28 bronze badges

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