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Interesting 21 Bountied Hot Week Month
2 votes
3 answers
149 views

Proving an heuristic bound involving the gaussian

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DroneBetter
  • 806
6 votes
2 answers
59 views

Cubic equation for closest point to a function

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Claude Leibovici
  • 298k
12 votes
3 answers
589 views

Die dilemma: get paid the sum or go home

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enryuxbt
  • 55
1 vote
2 answers
44 views

About the relationship between flatness as $R$-module of an ideal $K$ of a commutative ring $R$ and the flatness of the quotient $R/K$

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TY Mathers
  • 20.8k
0 votes
0 answers
5 views

Understanding Achim Klenke's Probability Theory, Proof of Theorem 15.34

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Plantation
  • 4,114
2 votes
1 answer
746 views

Unfair Coin Toss

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CommunityBot
  • 1
1 vote
0 answers
12 views

How to recover an affine group scheme

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NoetherNerd
  • 755
6 votes
2 answers
100 views

Connected components on a regular manifold

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quarague
  • 6,533
1 vote
1 answer
29 views

What is the shortest way to write an equivalent relation between n number of elements assuming that the transitive property is invalid.

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Greg Martin
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2 votes
0 answers
62 views
+300

Specific invariants for cyclic groups in Galois theory

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Simón Flavio Ibañez
  • 555
3 votes
1 answer
750 views

Hartman-Grobman Theorem - Necessary?

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CommunityBot
  • 1
7 votes
3 answers
804 views

Where do hash functions come from?

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Dan
  • 19.5k
3 votes
1 answer
773 views

"Functional example" of Cauchy sequence which is not convergent

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  • 1
1 vote
0 answers
95 views

Some examples of distributions of real random variables ( Achim Klenke, Probability Theory )

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Plantation
  • 4,114
21 votes
3 answers
395 views

Does $\sum_{n=0}^{\infty}\frac{(4n)!^2}{2^{8n}(n+1)^2(2n)!^4}$ has the proposed closed form?

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Stefan Lafon
  • 13.9k
2 votes
1 answer
29 views

How to find Farkas certificates?

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Siong Thye Goh
  • 155k
5 votes
1 answer
47 views

Does every Moore closure operator that satisfies $cl(\emptyset)=\emptyset$ arise as an intersection of Kuratowski closure operators?

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bof
  • 83.1k
0 votes
0 answers
32 views

Number of Solutions to $x^2 - y^2 \equiv n \pmod {m} $

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Group Drap
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44 votes
4 answers
42k views

Name for diagonals of a matrix

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Frank Rubin
  • 1
0 votes
1 answer
77 views

Trivial base change theorem in a Grothendieck site

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aeae
  • 547
1 vote
1 answer
752 views

Proof that for any n-sided polygon P, and any integer m greater than n, there is an m-sided polygon with the same area and perimeter as P?

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CommunityBot
  • 1
1 vote
0 answers
70 views

Does anything deeper hide behind this inequality?

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Auto Memories Doll
  • 19
4 votes
3 answers
205 views

Formula for cycloid?

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RobPratt
  • 52.5k
3 votes
1 answer
143 views

The name of an algebraic structure satisfying $y*(y*x)=x=(x*y)*y$

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RobPratt
  • 52.5k
5 votes
0 answers
110 views

How many points are needed to cover a whole lattice?

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RobPratt
  • 52.5k
22 votes
2 answers
3k views

Why are normal subgroups called "normal"?

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J. W. Tanner
  • 64.7k
6 votes
4 answers
9k views

What is the meaning of "independent events " and how can we logically conclude independence of two events in probability?

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WillG
  • 7,772
2 votes
1 answer
28 views

Proving $A = B$ under positive eigenvalue condition and equation $A^4 + 2A^3B = 2AB^3 + B^4$, without assuming commutativity

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user1551
  • 151k
4 votes
0 answers
88 views
+250

Over $\mathbb R^2$, given a tool that can $n$-sect an angle for any $n$, for which $n$ can you construct the $n$th root of any given $x > 0$?

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Sunny
  • 124
0 votes
1 answer
48 views

Average distance between all the points on 3d surface

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MsFormula
  • 1
0 votes
0 answers
21 views

Recommend a book on elliptic curves that can be used to learn cryptography?

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Bhaskar Vashishth
  • 11.8k
2 votes
3 answers
139 views

Recommended books in Quantum Field Theory for students major in mathematics

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Bhaskar Vashishth
  • 11.8k
0 votes
0 answers
11 views

Obtaining One of Multiple Subsets Coupon Collector Variant

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TheRealOne
  • 45
6 votes
1 answer
231 views

Find minimum of $\sum\limits_{i=1}^{n}a^2_{i}-2\sum\limits_{\mathrm{cyc}} a_1 a_2$ subject to $\sum\limits_{i=1}^n a_i = 1$

River Li's user avatar
River Li
  • 51.4k
1 vote
1 answer
55 views

Possible game states of card game Naishi

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HighDiceRoller
  • 1,280
0 votes
1 answer
29 views

Collinearity of $M', H, N'$ where $M', N'$ are reflections of midpoints across sides of the intouch triangle

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Jacob Phan
  • 315
4 votes
0 answers
62 views

The role of the de Rham theorem in $\nabla C^\infty(X)\cong C^\infty_0(X)$

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Arctic Char
  • 17.2k
2 votes
3 answers
338 views

Why are left and right cosets different in the non-normal case?

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Kan't
  • 5,510
1 vote
1 answer
179 views

Why does Fermat's little theorem not hold for all composite numbers?

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Gerry Myerson
  • 188k
1 vote
1 answer
138 views

A Collatz–type dynamical system with alternating multipliers ($3$ and $5$): three attractors and huge excursions

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mezzoctane
  • 1,853
2 votes
1 answer
104 views

Showing that a ring is Cohen-Macaulay

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walkar
  • 4,487
1 vote
0 answers
131 views

Replace a random variable by a "small" Gaussian

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tituf
  • 993
11 votes
10 answers
775 views
+200

Seeking different ways you can find $x=8$ in $(x-6)^3 = x^{\frac{1}{3}}+6$

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Daniel Smania
  • 9,163
0 votes
1 answer
931 views

Find the growth rate for $y=4^{x +1}$

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CommunityBot
  • 1
5 votes
1 answer
385 views

Compute $\sum_{k=1}^3\Big(\sum_{r=1}^\infty\Big(\frac{\tan\frac\theta{2^r}}{2^r}\Big)^k\Big)+\sum_{r=1}^\infty\frac{\tan\frac\theta{2^r}}{8^r}$

Integreek's user avatar
Integreek
  • 9,041
32 votes
6 answers
7k views

How to evaluate $\int_{0}^{2\pi}e^{\cos \theta}\cos( \sin \theta) d\theta$?

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Integreek
  • 9,041
0 votes
0 answers
15 views

Proof of a continuous map $h:S^1 \to X$ is nullhomotopic iff $h_*$ is trivial homomorphism without lifting

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khashayar
  • 2,674
2 votes
1 answer
61 views

Are there infinitely many odd composite numbers with digit-disjoint factorizations?

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Rushabh Mehta
  • 14k
0 votes
0 answers
10 views

Caro Wei bound with second neighbors in triangle free graphs

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Bruno Andrades
  • 5,594
4 votes
3 answers
391 views

Prove or disprove $\sum\limits_{\mathrm{cyc}} \sqrt{a_1a_2} \ge \sum\limits_{\mathrm{cyc}} \sqrt[3]{a_1a_2a_3}$ for $0 \le a_1 \le \cdots \le a_n$

River Li's user avatar
River Li
  • 51.4k
39 votes
1 answer
3k views

Is War necessarily finite?

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Rodrigo de Azevedo
  • 23.7k
2 votes
1 answer
765 views

Russian problem book on Real Analysis, Functional Analysis, Topology, et al.

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CommunityBot
  • 1
5 votes
2 answers
661 views

Name of the algebraic structure

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Anixx
  • 10.6k
0 votes
1 answer
34 views

Showing positive definite quadratic forms give the "most symmetrical" metrics over $\mathbb{R}^n$

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walldrum
  • 91
2 votes
0 answers
107 views

Self-adjoint operators with empty essential spectrum have compact resolvent

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Dean Miller
  • 9,347
3 votes
1 answer
928 views

Unique factorization fails in cyclotomic integers for $p=23$

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The Thin Whistler
  • 1,752
7 votes
5 answers
730 views

Canonicity of the push-pull map for sheaves of sets

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Yizhen Chen
  • 1,142
0 votes
1 answer
26 views

On the dimension of a linear system to give an embedding in $\mathbb{P}^3$

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KReiser
  • 76.4k
0 votes
1 answer
921 views

Prove that if $f$ is Riemann integrable on $[0,1]$, then $f$ is measurable and it equals to Lebesgue integral.

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CommunityBot
  • 1
0 votes
1 answer
51 views

Structure Theorem for finitely generated modules over PID Proof

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Aniruda Suswaram
  • 462
3 votes
0 answers
30 views

Computing the Positive Real Zero of the Symbolic Antiderivative of the Riemann-Zeta Function

Olive's user avatar
Olive
  • 41
2 votes
1 answer
2k views

How to find the conditional density of $X$ given an event $A$ has happened?

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I love yogurt
  • 1
10 votes
0 answers
281 views

Why is the Whitehead product $[\iota_2, \eta] : \pi_4\mathbb{S}^2$ trivial?

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Crimson-bear
  • 792
0 votes
2 answers
778 views

How would I find the Context Free Grammar for the complement of $L = \{a^n \mid n\geq 0\}$? The alphabet is $\{a\}$.

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Tankut Beygu
  • 4,959
0 votes
0 answers
27 views

Estimates in Hahn decomposition for measures of finite positive variation

shark's user avatar
shark
  • 1,881
3 votes
4 answers
4k views

How to change the sign of the Dirac delta function argument?

Dan's user avatar
Dan
  • 19.5k
1 vote
1 answer
18 views

Characterization of the $\sigma$-ideal generated by wandering sets for a measureable system $(X,\mathcal{B},T)$

Matsmir's user avatar
Matsmir
  • 4,224
3 votes
1 answer
71 views

Is this set of Diophantine equations independent?

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mezzoctane
  • 1,853
-2 votes
0 answers
40 views

$\sum_{j=2}^{k+1} \sum_{p=k+1}^\infty \frac{1}{p j^p} + \sum_{j=k+2}^\infty \sum_{p=2}^\infty \frac{1}{p j^p}<\frac{1}{k+1}$ for all $k \ge 2$.

Jose1's user avatar
Jose1
  • 569
0 votes
1 answer
83 views

I'm struggling with a logic problem and need some help understanding my mistake

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naturallyInconsistent
  • 677
5 votes
1 answer
301 views

Which theorems and definitions do I need to know to prove the impossible chessboard puzzle has a solution for every number of squares?

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camille_2718
  • 21
2 votes
0 answers
46 views

Contractibility of topological embeddings

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FD_bfa
  • 4,927
-1 votes
0 answers
23 views

CW-structure on $ X = S^1\times\partial D^2 \;\cup\; \{x,y\}\times D^2 \subset T=S^1\times D^2. $

Ben Steffan's user avatar
Ben Steffan
  • 11k
1 vote
1 answer
57 views

In how many ways a mouse can get in the $j$-th cell in the $i$-th row?

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Mathemagician314
  • 2,421
2 votes
2 answers
117 views

Simplest Fraction in Interval

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Oscar Lanzi
  • 51.5k
11 votes
8 answers
2k views

Finding $ \int^1_0 \frac{\ln(1+x)}{x}dx$

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xpaul
  • 49.4k
0 votes
1 answer
29 views

Equivalences of a generator module

FShrike's user avatar
FShrike
  • 48.3k
1 vote
1 answer
749 views

One sided limit of composite function

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CommunityBot
  • 1
3 votes
1 answer
58 views

Prove that the sum of concatenation of all nonzero single digits (except $0$ in base 1) in first $2026$ bases is not a square

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Adam AbdulAlim
  • 56
0 votes
0 answers
20 views

Reference for classical action of the standard height function on the two-torus written as sum of elementary and elliptic integrals?

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J. W. Tanner
  • 64.7k
6 votes
1 answer
258 views

Why Bohr's definition of almost periodicity?

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N. S.
  • 135k
3 votes
0 answers
51 views

For which $n$ and $k$ does there exist a "cursed" centrifuge arrangement?

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Aaron
  • 51
1 vote
0 answers
29 views

Find the maximum of the following function $Q(x_1, x_2, ..., x_N)$ subject to some constraints.

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Thanos
  • 179
0 votes
0 answers
37 views

Confusion regarding Tangent Basis

Fin H's user avatar
Fin H
  • 107
17 votes
2 answers
513 views

Help with $\int_{0}^{\pi /4} x^3 (\sqrt{\tan (x)} + \sqrt{\cot (x)}) dx$

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Dr. Wolfgang Hintze
  • 13.5k
133 votes
29 answers
26k views

Different ways to prove there are infinitely many primes?

KCd's user avatar
KCd
  • 57.1k
12 votes
1 answer
386 views

Convergence of Laplace transform

Srini's user avatar
Srini
  • 2,428
3 votes
1 answer
110 views

The number of strings with bounded partial sums

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ploosu2
  • 12.7k
1 vote
0 answers
35 views

Determining the location of portals using air pressure

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user110391
  • 1,243
0 votes
0 answers
33 views

Lie groupoid equivalence implies homotopy equivalence of classifying spaces

Y.Wayne's user avatar
Y.Wayne
  • 377
3 votes
1 answer
143 views

$=$-sign within factorial: is this an ancient notation for the Pochhammer symbol or just a typo?

Vincent's user avatar
Vincent
  • 11.5k
2 votes
3 answers
329 views

Closed form for $\int_{0}^{1} \frac{\tan^{-1} x}{1+x+x^2}dx$

FDP's user avatar
FDP
  • 16.2k
0 votes
1 answer
768 views

Tangent Space Projector from Riemannian Metric

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CommunityBot
  • 1
0 votes
0 answers
14 views

Properties of self-concordant functions

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jayant
  • 153
3 votes
7 answers
408 views

Proof that limit points are unique

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C Squared
  • 3,817
16 votes
2 answers
1k views

The (alternating) sum of reciprocals of ${n\choose 0}, {n\choose 1}, ... {n\choose n}$

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DroneBetter
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