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.

Kolakoski sequence

Awarded Oct 25 at 20:54

colt_browning

3,7701 gold badge15 silver badges33 bronze badges

Why is there an $N(\varepsilon)$ such that $|P_n(x)-F(x)|\le 2\varepsilon,\ \forall x\in[0,1]$ in the Weierstrass approximation theorem?

Awarded Oct 25 at 15:47

Anne Bauval

51.3k13 gold badges36 silver badges82 bronze badges

How can I prove $f(x) = x^n-a \in F[X]$ is separable?

Awarded Oct 25 at 6:35

Afntu

4,2853 gold badges24 silver badges37 bronze badges

This proof in my textbook involving the pumping lemma appears incorrect - is it?

Awarded Oct 24 at 13:00

wece

2,9621 gold badge16 silver badges27 bronze badges

Is the Law of Excluded Middle needed to prove $(\alpha \to (\beta \land \lnot\beta)) \to \lnot\alpha$?

Awarded Oct 23 at 20:26

Carl Mummert

87k13 gold badges179 silver badges326 bronze badges

Prove that the dimension of the centralizer of a Jordan block is $n$

Awarded Oct 23 at 15:24

Nothing special

3,9451 gold badge9 silver badges29 bronze badges

$x_{n+1}=(-1)^{n+1}|x_n+x_{n-1}|$ Prove that there exists a sub-sequence of $(x)_n$ that converges to $0$, nomatter how we choose $x_0$ and $x_1$.

Awarded Oct 22 at 13:09

Brian M. Scott

635k57 gold badges831 silver badges1.4k bronze badges

Must the singular solution of ODE be the envelope of the family of general solutions?

Awarded Oct 22 at 10:49

shubham singh

474 bronze badges

Find number of $r$-element subset of $S$ satisfying a property

Awarded Oct 22 at 7:09

Artyom Dmitriev

6197 silver badges19 bronze badges

Cohomology theory for vertex operator algebras?

Awarded Oct 22 at 3:03

mathisfun

1015 bronze badges

Group action where all stabilizers are equal

Awarded Oct 22 at 2:33

Paul Rebenciuc

9591 gold badge8 silver badges34 bronze badges

Problem of finding strong maxima or minima of a functional

Awarded Oct 21 at 19:46

Gonçalo

16.5k16 gold badges19 silver badges63 bronze badges

Why is "antiderivative" also known as "primitive"?

Awarded Oct 21 at 13:57

Michael E2

1,61917 silver badges23 bronze badges

What is $\lim_{t \to 0} \left[ {k \atop t} \right] \zeta(t+1) $?

Awarded Oct 21 at 9:43

DroneBetter

6744 silver badges18 bronze badges

Integrals of the form $\int x^m(a+bx^n)^P\mathrm dx$

Awarded Oct 21 at 4:22

Integreek

9,0313 gold badges23 silver badges60 bronze badges

Homotopy equivalence of realization of nerve of a cover.

Awarded Oct 20 at 22:12

Thorgott

18.7k2 gold badges24 silver badges49 bronze badges

Find the general solution of $4u_{xx}+5u_{xy}+u_{yy}+u_x+u_y=2$

Awarded Oct 20 at 19:57

Aleksas Domarkas

2,5218 silver badges13 bronze badges

(post deleted or otherwise unavailable)

Awarded Oct 20 at 19:35

Arina Pambukyan

863 bronze badges

Difference between support of a section and nonvanishing locus of a section.

Awarded Oct 20 at 11:37

Elías Guisado Villalgordo

5,19517 silver badges44 bronze badges

Is it necessary for the Imaginary-axis to be perpendicular to the Real-axis?

Awarded Oct 20 at 3:11

mjw

8,8711 gold badge9 silver badges28 bronze badges

Compute the integral $\int_{|z|=\rho}|z-a|^{-4}|dz|$ with $|a|\neq \rho$

Awarded Oct 18 at 18:03

Skywalker

4812 silver badges11 bronze badges

Wavefront Set of the Heaviside Function

Awarded Oct 18 at 15:21

Baol

6523 silver badges10 bronze badges

What is the proof-theoretic ordinal of $ \mathsf{PA}+\mathsf{TI}(\prec_{\varepsilon_0})$?

Awarded Oct 18 at 7:24

C7X

1,7617 silver badges26 bronze badges

Generating function of the sequence $\binom{2n}{n}^3H_n$

Awarded Oct 17 at 22:53

User-Refolio

1,1816 silver badges33 bronze badges

Why is the expected payout equal to the $p_1$?

Awarded Oct 17 at 21:28

pinton jol

4151 silver badge20 bronze badges

Self-intersections of a Lissajous curve

Awarded Oct 17 at 17:16

hbghlyj

6,0872 gold badges12 silver badges37 bronze badges

Prove that $5\mid 2^n +3$ $\iff$ $4\mid (n-1)$

Awarded Oct 17 at 10:10

nonuser

92.5k20 gold badges112 silver badges220 bronze badges

"Stacks project" - construction of Segre embedding - a clarification

Awarded Oct 17 at 6:51

Elías Guisado Villalgordo

5,19517 silver badges44 bronze badges

When do identities proven using a specific representation of a lie algebra hold generally?

Awarded Oct 16 at 23:58

Abezhiko

15k2 gold badges10 silver badges31 bronze badges

Inverse of prime counting function

Awarded Oct 16 at 6:28

François Huppé

1,6719 silver badges18 bronze badges

Are there any solutions to the following congruences where $t^3 \not\equiv 1 \pmod {p^3}$

Awarded Oct 15 at 21:01

user1691820

394 bronze badges

Solving third order linear ODE using symmetric square basis

Awarded Oct 15 at 16:54

Travis Willse

109k13 gold badges148 silver badges288 bronze badges

Can we do better than Newton's method for optimisation?

Awarded Oct 15 at 16:54

Guillermo Aparicio-Estrems

464 bronze badges

Characterizing the sum of $m$ inverse-gamma random variables

Awarded Oct 15 at 14:43

framago

1,9541 gold badge8 silver badges19 bronze badges

Prove that the Zolotarev symbol is the same as Legendre and Jacobi symbols

Awarded Oct 15 at 8:11

user0

3,7371 gold badge21 silver badges67 bronze badges

What are some good expositions of the Hilbert-Bernays-Löb derivability conditions for PA?

Awarded Oct 15 at 1:35

Léon Probst

1387 bronze badges

How general is the tennis racket theorem?

Awarded Oct 14 at 17:26

nesqwa

4715 bronze badges

Sum involving Stirling number of first kind

Awarded Oct 14 at 14:27

DroneBetter

6744 silver badges18 bronze badges

Set of cusps of the congruence subgroup $\Gamma_{1}(p)$, where $p$ is an odd prime number.

Awarded Oct 14 at 14:06

p. k. a. Siewert

314 bronze badges

Prove that $\int_0^1 |f(x) - g(x)| dx \leq \frac{1}{2}$ for two increasing functions in a $1 \times 1$ square

Awarded Oct 14 at 1:41

VV_721

9011 gold badge3 silver badges18 bronze badges

Is the extension of a torsion free group by a torsion free group necessarily torsion free?

Awarded Oct 13 at 19:39

Student

631 silver badge6 bronze badges

$f(f(z)) = z, f' (f'(z)) = z $?

Awarded Oct 13 at 9:37

Thinh Dinh

9,8906 gold badges22 silver badges59 bronze badges

A prime number that is a value of a simultaneous system of diagonal binary quadratic forms

Awarded Oct 12 at 22:21

Servaes

68.8k8 gold badges83 silver badges177 bronze badges

Index of subgroups in infinite p-group

Awarded Oct 12 at 16:41

Dabouliplop

2,14011 silver badges23 bronze badges

A $p$-biased centered random walk never leaves $[-1,1]$ with probability $\ge e^{-np(1-p)}$.

Awarded Oct 12 at 15:00

Thomas Ahle

5,91529 silver badges57 bronze badges

Classification of analytic involutions

Awarded Oct 12 at 12:11

Cactus

10.2k1 gold badge7 silver badges29 bronze badges

Travelling soliton wave solution to the $1$-dimensional Gross-Pitaevskii equation

Awarded Oct 12 at 3:27

Misty

715 bronze badges

Proof of Paley-Zygmund inequality (lower bound for upper tail of square-integrable random variables)

Awarded Oct 11 at 22:38

Math1000

38.3k5 gold badges41 silver badges105 bronze badges

Tesselation Combinatorics Problem

Awarded Oct 11 at 21:13

Narasimham

42.7k7 gold badges46 silver badges117 bronze badges

Question about "Klein Bottle" in 3 dimension. Algebraic Topology, Hatcher. Exercise 1.2.12.

Awarded Oct 11 at 18:48

C Squared

3,8181 gold badge12 silver badges38 bronze badges

How to evaluate the following definite integral?

Awarded Oct 11 at 15:38

user170231

27.1k3 gold badges49 silver badges96 bronze badges

Gibbs' inequality; continuous case

Awarded Oct 11 at 11:12

Ari.stat

5233 silver badges13 bronze badges

Is the argument in the "100 people with green eyes" riddle correct?

Awarded Oct 11 at 8:31

Bctolman

213 bronze badges

Pseudo-primes with non-prime bases

Awarded Oct 11 at 4:06

Eberhard

3333 silver badges12 bronze badges

Calculating L-smoothness constant for logistic regression.

Awarded Oct 10 at 18:26

Tien-en Chang

212 bronze badges

Schauder fixed point theorem

Awarded Oct 10 at 18:01

Predrag Punosevac

3981 silver badge12 bronze badges

Dudley’s exercise on finitely additive probabilities

Awarded Oct 10 at 16:36

Caleb Stanford

47.5k8 gold badges76 silver badges180 bronze badges

Higher interior regularity

Awarded Oct 10 at 16:36

K.defaoite

14.4k4 gold badges26 silver badges56 bronze badges

Second existence theorem for weak solution of uniformly elliptic PDE in Evans

Awarded Oct 10 at 16:36

K.defaoite

14.4k4 gold badges26 silver badges56 bronze badges

Are there affine planes with no abelian group of translations?

Awarded Oct 9 at 16:36

Taras Banakh

7783 silver badges11 bronze badges

Prev 1 2

4 5

…

385 Next