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Enlightened

First to answer and accepted with score of 10 or more. This badge can be awarded multiple times.

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What are the functions obtained by complex polynomials evaluated at complex numbers

Awarded 10 hours ago

José Carlos Santos

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a example of two space that are homotopy equivalent but not homeomorphic

Awarded 11 hours ago

Dan Rust

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Is there a reason why the Maclaurin coefficients of the Riemann zeta function are asymptotically close to -1?

Awarded 17 hours ago

Greg Martin

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Why is propositional logic not Turing complete?

Awarded yesterday

camccann

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If $a^2 + b^2 + c^2 = 1$, what is the the minimum value of $\frac {ab}{c} + \frac {bc}{a} + \frac {ca}{b}$?

Awarded yesterday

Anon

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Is $\varphi$ the most irrational number?

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Ty Jensen

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Is n-euclidean space a quotient of m-euclidean space?

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freakish

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Exponential decay estimate for $(x,t) \in U_T$

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Jose27

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What does the symbol $\sum_{\mathrm{cyc}}$ mean?

Awarded yesterday

Simon S

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bivariate Yoneda lemma

Awarded 2 days ago

Derek Elkins left SE

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How to prove that if $a\equiv b \pmod{kn}$ then $a^k\equiv b^k \pmod{k^2n}$

Awarded 2 days ago

Paul

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How do we know if a function has an elementary inverse?

Awarded Jul 18 at 6:42

IV_

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If every composition of a differentiable path and a function is differentiable at 0, means the function is differentiable at 0

Awarded Jul 17 at 19:20

PhoemueX

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How to prove the modular multiplication property?

Awarded Jul 17 at 18:49

Simply Beautiful Art

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Solve $x^3+x^2+x=-\frac{1}{3}$ in $\mathbb{R}$

Awarded Jul 16 at 20:39

cansomeonehelpmeout

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Constructing the interval [0, 1) via inverse powers of 2

Awarded Jul 16 at 17:48

Joshua Tilley

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Infinity matrix norm example

Awarded Jul 16 at 17:48

Will Jagy

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Top Cohomology group of a "punctured" manifold is zero?

Awarded Jul 16 at 11:42

Najib Idrissi

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Is selecting a random person from an infinite population of people an invalid premise to begin with?

Awarded Jul 16 at 9:14

Qiaochu Yuan

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Show that $\frac{1}{(a+b)(c+1)}+ \frac{1}{(c+b)(a+1)}+ \frac{1}{(a+c)(b+1)} \leq \frac{3}{4}$

Awarded Jul 16 at 4:51

Sharky Kesa

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Abelianization of free product is the direct sum of abelianizations

Awarded Jul 16 at 4:51

Captain Lama

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Indefinite integral which is not differentiable

Awarded Jul 16 at 0:34

Hans Lundmark

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An operator has closed range if and only if the image of some closed subspace of finite codimension is closed.

Awarded Jul 15 at 15:10

Martin

8,60141 silver badges70 bronze badges

(post deleted or otherwise unavailable)

Awarded Jul 15 at 11:35

badjohn

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Does the unit generate the additive group in a unital ring with cyclic additive group?

Awarded Jul 15 at 6:55

Sebastian Monnet

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$a^{\phi (n) +1} \equiv a \pmod{\! n}; $ Carmichael generalization of Fermat & Euler theorems.

Awarded Jul 15 at 2:16

Bill Dubuque

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How can I learn how to solve hard problems like this Example?

Awarded Jul 14 at 22:48

Prem

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Lang's elementary divisors theorem is wrong

Awarded Jul 14 at 20:41

Fançois Gatine

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closed point of a locally finite $k$-scheme

Awarded Jul 14 at 18:42

Hanno

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Maximising det(AB) with respect to B

Awarded Jul 14 at 18:42

user1551

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Can a nonconstant function that is invariant to this affine transformation exist?

Awarded Jul 14 at 14:20

Qiaochu Yuan

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Example of a section $s$ of a presheaf $\mathcal{F}$ which is not determined by $\{ s_x \}_{x}$.

Awarded Jul 14 at 12:37

Georges Elencwajg

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History of terminology: sheaves, presheaves, etc.

Awarded Jul 14 at 12:37

Georges Elencwajg

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Sample path of Brownian motion Hölder continuous?

Awarded Jul 13 at 22:49

shalop

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Is a metric/distance not a measure?

Awarded Jul 13 at 21:12

Anakhand

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Norm of triangular matrix with constant rows $\approx \sqrt{d \log 2}$?

Awarded Jul 13 at 2:55

abacaba

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Group of order $n$ is a subgroup of $S_{n-1}$

Awarded Jul 12 at 20:49

Derek Holt

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Are the bounded Lipschitz functions dense in $L^1(\mu)$?

Awarded Jul 12 at 18:47

MaoWao

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How can I divide by a matrix?

Awarded Jul 12 at 14:56

5xum

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If quadratic variation of a local martingale is zero then it is itself zero

Awarded Jul 12 at 14:56

saz

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Positive sum can always be presented as a sum with strictly positive incremental sub-sums

Awarded Jul 12 at 8:34

Martin R

117k8 gold badges102 silver badges193 bronze badges

Prove ${_4 F_3} \left(\frac12, \frac12, 1, 1; \frac34, \frac54, \frac32; \frac14 \right)= \frac14 \left(\frac{\pi^2}{4}+\log^2 (2+\sqrt{3} ) \right)$

Awarded Jul 12 at 5:16

Zacky

28.1k2 gold badges86 silver badges165 bronze badges

Why do cubic equations always have at least one real root, and why was it needed to introduce complex numbers?

Awarded Jul 11 at 18:04

Ethan Bolker

97.7k7 gold badges115 silver badges205 bronze badges

For every real function $f$, is there a strictly increasing real function $g$ above $f$?

Awarded Jul 11 at 18:04

Martin R

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Intuitive and convincing argument that functions are vectors

Awarded Jul 11 at 15:03

rschwieb

156k15 gold badges172 silver badges413 bronze badges

Calculate the commutator subgroup of $S_4$

Awarded Jul 11 at 11:25

Andreas Caranti

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Analytic "Lagrange" interpolation for a countably infinite set of points?

Awarded Jul 11 at 6:05

lhf

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Does there exist a nontrivial "good" set?

Awarded Jul 11 at 3:56

Servaes

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Inner product on the tensor product of Hilbert spaces

Awarded Jul 10 at 19:45

agt

4,82224 silver badges38 bronze badges

Upper Bound on $\mathbb E[\sqrt{X}]$ with $X\sim\operatorname{Bin}(n,\frac{1}{n})$ that is not Jensen

Awarded Jul 10 at 18:20

Mittens

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Can $10^m+10^n+10^p+1$ be a Perfect Square Number?

Awarded Jul 10 at 16:13

Dhruv Tiwari

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The center of gravity of a triangle on a parabola lies on the axis of symmetry

Awarded Jul 10 at 16:13

Semiclassical

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$SL_2(\mathbb{Z})$ is an amalgamated product

Awarded Jul 10 at 14:13

Derek Holt

92.2k5 gold badges76 silver badges132 bronze badges

Application of the Burkholder Davis Gundy inequality

Awarded Jul 10 at 8:05

saz

121k13 gold badges154 silver badges252 bronze badges

Evaluate $\int_{0}^{1} \frac{\ln x}{(1+8x^2)\sqrt{1-x^2}} dx$

Awarded Jul 10 at 5:10

whatamidoing

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Is there a set of all set-theoretical truths?

Awarded Jul 9 at 22:46

Noah Schweber

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What is the surface by identifying antipodal points of a 2-torus embedded in $\mathbb{R}^3$?

Awarded Jul 9 at 10:55

Milo Brandt

61.1k5 gold badges109 silver badges192 bronze badges

Prove if a power series is zero on an interval then all coefficients are zero

Awarded Jul 9 at 0:22

Davide Giraudo

175k69 gold badges262 silver badges408 bronze badges

Confusion on defining uniform distribution on hypersphere and its sampling problem

Awarded Jul 8 at 17:26

Qiaochu Yuan

432k53 gold badges967 silver badges1.4k bronze badges

Sufficient Conditions for Ricci Tensor to be Diagonal

Awarded Jul 8 at 15:25

Henry T. Horton

18.5k5 gold badges62 silver badges79 bronze badges

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