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Interesting 42 Bountied Hot Week Month
0 votes
1 answer
39 views

Why is $ V \longrightarrow V: v \mapsto \pi(g)(v)$ an endomorphism of $G$-modules?

freakish's user avatar
freakish
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15 votes
0 answers
370 views
+250

Where are the other Pythagorean Theorems?

N. F. Taussig's user avatar
N. F. Taussig
  • 75.9k
-1 votes
0 answers
17 views

Closed convex subset that is unbounded

Mark Kamsma's user avatar
Mark Kamsma
  • 12.7k
0 votes
0 answers
2 views

Angle from points coordinates in n dimensions

ice-wind's user avatar
ice-wind
  • 133
-3 votes
0 answers
30 views

how to calculate the arg(ζ(0.5+iT)) where ζ is the zeta function

Fatima Majeed's user avatar
Fatima Majeed
  • 1
5 votes
0 answers
139 views

Can this be done? Split Pascal's triangle (without the $1$s) with a straight line into two regions of equal sums.

Dan's user avatar
Dan
  • 15.9k
0 votes
0 answers
10 views

Is this a valid way of proving this series converges?

Bill Cogn's user avatar
Bill Cogn
  • 41
-2 votes
0 answers
26 views

Prove that sin(x^2)>(sin(x))^2

Carloss's user avatar
Carloss
  • 1
1 vote
1 answer
131 views

Characterisation of affine transformations

gpassante's user avatar
gpassante
  • 1,030
1 vote
0 answers
8 views

Concentration bounds for dependent Bernoulli random variables

Mixi Andrew's user avatar
Mixi Andrew
  • 13
0 votes
0 answers
5 views

How to deal with total derivative in the arc length formula for a 2D function?

Balfar's user avatar
Balfar
  • 133
1 vote
1 answer
37 views

osculating plane for linear motion

Hosam H's user avatar
Hosam H
  • 19k
0 votes
1 answer
16 views

Could spectral methods solve first-order differential equations?

Nikola Ristic's user avatar
Nikola Ristic
  • 903
-1 votes
0 answers
10 views

Order between probability of independent and dependent events

the_elder's user avatar
the_elder
  • 347
0 votes
0 answers
18 views

What can be said about $f(A)$ provided $f$ is a linear map?

math student's user avatar
math student
  • 1,095
0 votes
2 answers
41 views

Continuity at a point versus continuity after algebraic manipulation

Martin Brown's user avatar
Martin Brown
  • 101
0 votes
0 answers
13 views

Goldbach function and primes

Craw Craw's user avatar
Craw Craw
  • 77
1 vote
1 answer
1k views

Path traced by a ladder sliding down a wall

Community's user avatar
CommunityBot
  • 1
0 votes
0 answers
13 views

Inequality of inclusion-exclusion terms

Tobias's user avatar
Tobias
  • 15
1 vote
1 answer
30 views

Closed image of bounded linear operators

El_mago's user avatar
El_mago
  • 116
0 votes
2 answers
46 views

Let $a, b, c$ are positive real numbers, such that $a+b+c=1$. Then prove that $\frac{a-bc}{a+bc} +\frac {b-ca}{b+ca} +\frac {c-ab}{c+ab} \leq \frac32$

Calvin Lin's user avatar
Calvin Lin
  • 66.7k
0 votes
0 answers
3 views

Expression of a Hawkes process

coboy's user avatar
coboy
  • 1,262
0 votes
0 answers
4 views

Proof of gradient of L2-norm squared?

DataStatsExplorer's user avatar
DataStatsExplorer
  • 13
3 votes
0 answers
141 views
+50

How to prove $\sqrt{2a+3bc}+\sqrt{2b+3ca}+\sqrt{2c+3ab}\ge 3\sqrt{5}$?

Anonymous's user avatar
Anonymous
  • 814
0 votes
0 answers
8 views

Deriving Newton’s gravitational potential through Poisson’s equation for gravitational field.

Sunny Wong's user avatar
Sunny Wong
  • 91
3 votes
2 answers
235 views

Are all covers fundamental?

Arshak Aivazian's user avatar
Arshak Aivazian
  • 890
1 vote
1 answer
22 views

Linear Algebra: The inverse of an injective function

Dmitry Ivanov's user avatar
Dmitry Ivanov
  • 113
0 votes
0 answers
7 views

If $f \in L^2(\mathbb{R}^n)$ and $T \in S^*(\mathbb{R}^n)$. Then: there exists $F \in L^2(\mathbb{R}^n)$ such that $\hat{T}_f=T_F$

sunflower234's user avatar
sunflower234
  • 355
3 votes
2 answers
194 views

Prove $f\left(nx\right)\leq nf\left(x\right).$

Yu Li's user avatar
Yu Li
  • 68
0 votes
0 answers
16 views

What is an "imaginary subspace" (of $\mathbb C$, or of $\mathbb H$)?

mma's user avatar
mma
  • 1,909
0 votes
1 answer
22 views

Proof that the non simply normal numbers in base 2 are uncountable?

Andrey Shlykov's user avatar
Andrey Shlykov
  • 9
-1 votes
0 answers
7 views

Convergence of square root differences of densities

harisf's user avatar
harisf
  • 305
0 votes
0 answers
17 views

Divergent sequence proof verification

Snake Detection Hypothesis's user avatar
Snake Detection Hypothesis
  • 41
1 vote
2 answers
30 views

Number of heads $\geq 15 \space + $ number of tails or number of tails $\geq 25 \space + $ number of heads

Matthew Esmaili's user avatar
Matthew Esmaili
  • 182
3 votes
0 answers
102 views

Suppose $0\to A\to B\to C\to D\to 0$ is exact. Let $0\to A[2]\to B[2]\to C[2]\to X\to 0$ be an exact sequence. Then, $X [2]$ is finite.

Just a user's user avatar
Just a user
  • 13.3k
0 votes
1 answer
24 views

Why $\cos(df_p(v_1),df_p(v_2))=\cos(v_1,v_2)\Rightarrow|df_p(v)|^2=\lambda(p)^2 |v|^2$?

Elliot Herrington's user avatar
Elliot Herrington
  • 2,190
1 vote
0 answers
26 views

Will the expanding cube look gray?

Cauchy's Sequence's user avatar
Cauchy's Sequence
  • 862
-2 votes
0 answers
17 views

Nonconvex optimization problem: Project a vector to the l0-norm space

Hao WANG's user avatar
Hao WANG
  • 71
2 votes
0 answers
27 views

Evaluating the product of two derivatives

Peter Petrov's user avatar
Peter Petrov
  • 43
0 votes
0 answers
16 views

On kernels and stalks of sheaves.

not an analyst's user avatar
not an analyst
  • 972
0 votes
0 answers
17 views

Ito's Lemma for Process given Generator

Florian Ente's user avatar
Florian Ente
  • 181
0 votes
0 answers
10 views

How to prove Exact finite sums involving multiple factorial functions in Wiki?

Michh's user avatar
Michh
  • 2,476
4 votes
2 answers
180 views

How to write $\min\{a,k\}+\min\{b,k\}$ as one min?

5xum's user avatar
5xum
  • 122k
0 votes
0 answers
15 views

Stuck at showing recursion property $q_n=c_nq_{n-1}+q_{n-2}$ of the continuants $q_n$ of $x$'s continued fraction expression $x=\frac{p_n}{q_n}$.

Cartesian Bear's user avatar
Cartesian Bear
  • 879
0 votes
0 answers
22 views

Suppose $\mu$ is a finite measure, show that $\phi_\mu(t):\int_R e^{itx}d \mu (x)$ is continous.

Dave's user avatar
Dave
  • 79
0 votes
0 answers
21 views

"mean value problem" for 2-ary functions

finiteness's user avatar
finiteness
  • 703
1 vote
1 answer
29 views

Writing symmetric polynomials in term of elementary symmetric polynomials...

Yuval's user avatar
Yuval
  • 3,349
2 votes
1 answer
42 views

How to prove $\sqrt{(a+b+c)\left(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\right)}\ge 3+\frac{1}{3}\sum_{cyc}\left(\frac{b-c}{b+c}\right)^2.$

d8g3n1v9's user avatar
d8g3n1v9
  • 43
2 votes
1 answer
44 views

$I_n:=\int_1^n\ln(t)dt$, $u_n:=\ln(n!)-\frac{1}{2}\ln(n)$, $L:=\lim_{x\to \infty}(I_n-u_n)$, $c=1-L$. Show that $n!~\frac{n^n}{e^n}\sqrt ne^c$

dreamare's user avatar
dreamare
  • 21
1 vote
0 answers
12 views

Non-zero measure sets that are stable under composition

Carlyle's user avatar
Carlyle
  • 2,048
0 votes
0 answers
3 views

Resource recommendations for Frobenius inner product and orthogonal matrices

Nick's user avatar
Nick
  • 11
0 votes
1 answer
39 views

Is $\circledcirc\equiv\omega *$? Or is $\omega * \in \circledcirc$?

Prem's user avatar
Prem
  • 7,321
4 votes
1 answer
82 views

Calculation of $\int \frac{ A_0 + A_1\cos{(a_1x)} + A_2\cos{(a_2x)} }{ [ B_0 + B_1\cos{(a_1x)} + B_2\cos{(a_2x)} ]^2 } dx $

Michael Gaitanas's user avatar
Michael Gaitanas
  • 41
1 vote
1 answer
48 views

Find a explicit formula for $f(x)$ where $\phi(t)=\int_0^x f(t)dt=\int_x^1 t^2f(t)dt+\frac{x^{16}}{8}+\frac{x^{18}}{9}+C$

Fergns Qian's user avatar
Fergns Qian
  • 113
-1 votes
0 answers
35 views

I need a little help with this series

IraeVid's user avatar
IraeVid
  • 2,855
0 votes
1 answer
21 views

Showing Runge-Kutta implicit method local truncation error

Nicholas Simafranca's user avatar
Nicholas Simafranca
  • 106
0 votes
0 answers
13 views

Proposed analysis techniques - optimal decision given expectation

Mathman's user avatar
Mathman
  • 11
5 votes
1 answer
192 views

Anyone knows a transformation that can lump non-zero values in a matrix together?

Rócherz's user avatar
Rócherz
  • 3,866
0 votes
0 answers
13 views

Showing that field embedding exists

user1011's user avatar
user1011
  • 1
0 votes
0 answers
4 views

Region of zeros of linear combination of polynomials

Seyed Amir Hosseini Dastja's user avatar
Seyed Amir Hosseini Dastja
  • 1
-2 votes
0 answers
17 views

Solve the pde $z+xp-x^2 y q^2-x^3 p q$.

J.G.'s user avatar
J.G.
  • 115k
1 vote
0 answers
17 views

Balanced graph partitioning for d regular graphs

Inon Kaplan's user avatar
Inon Kaplan
  • 11
5 votes
1 answer
281 views

Is countable choice enough to prove that there are continuum-many Borel sets?

Elliot Glazer's user avatar
Elliot Glazer
  • 1,360
0 votes
0 answers
9 views

Use $\Pr(|Y-\mathbb EY| \le a) > 1-\delta$ to simplify $\Pr(X \le Y \mid Y = y) > 1-\delta$.

Flo's user avatar
Flo
  • 331
0 votes
0 answers
23 views

Is the ideal of projective variety homogeneous when the projective variety is defined over a ring

Zirui Yan's user avatar
Zirui Yan
  • 1
0 votes
0 answers
11 views

Endomorphisms of algebra representations form the opposite algebra: injection in one direction is not obvious

Daigaku no Baku's user avatar
Daigaku no Baku
  • 1
2 votes
1 answer
32 views

Is the tensor product of W*-algebras commutative?

MaoWao's user avatar
MaoWao
  • 14.8k
3 votes
0 answers
16 views

When are all normal subgroups of a direct product of finite groups a direct product of normal subgroups?

Martin Brandenburg's user avatar
Martin Brandenburg
  • 159k
5 votes
1 answer
89 views

Proof that a series converges to zero

Davide Giraudo's user avatar
Davide Giraudo
  • 170k
1 vote
0 answers
28 views

How to draw a parabola using basic equipment?

Dan's user avatar
Dan
  • 15.9k
4 votes
1 answer
553 views

On the real roots of the chromatic polynomial

Rócherz's user avatar
Rócherz
  • 3,866
1 vote
1 answer
23 views

A question regarding the divisibility of Fibonacci sequence

bof's user avatar
bof
  • 76.7k
1 vote
1 answer
29 views

Derivative of a matrix times a vector within an exponential function

Shuai Yang's user avatar
Shuai Yang
  • 71
0 votes
0 answers
20 views

suppose that $\{A_i\}$ is the set of bounded subsets of $\mathbb{R}^n$. Prove that $\{A_i\}$ has no greatest element.

Asaf Karagila's user avatar
Asaf Karagila♦
  • 390k
5 votes
3 answers
1k views

CCRT = Constant case CRT: $ $ if $\,p,q\,$ are coprime then$\,x\equiv a\pmod{\! p},\ x\equiv a\pmod{\! q}\iff x\equiv a\pmod{\!pq}$

IraeVid's user avatar
IraeVid
  • 2,855
-1 votes
0 answers
11 views

Find the values of integers A and N (≥A) for which (3ᴬ - 2ᴬ)/(2ᴺ - 3ᴬ) is a positive integer

WeCanDoItGuys's user avatar
WeCanDoItGuys
  • 21
6 votes
2 answers
62 views

counting sequences of elements of the set {1,2,3,4} with given property

N. F. Taussig's user avatar
N. F. Taussig
  • 75.9k
0 votes
0 answers
29 views

Simple random walk, Martingales, stopping time

Win_odd Dhamnekar's user avatar
Win_odd Dhamnekar
  • 1,002
0 votes
1 answer
15 views

A question on numerical approximation scheme for an integral and functions for which the scheme is exact

MathRookie2204's user avatar
MathRookie2204
  • 424
3 votes
1 answer
241 views

Concrete category whose objects are not sets

visual-theory's user avatar
visual-theory
  • 1
0 votes
0 answers
9 views

Difusion - line methods - dissolution of minerals

Rócherz's user avatar
Rócherz
  • 3,866
0 votes
0 answers
23 views

Geometry of underdetermined regression loss function in $n$-dimensions

Tianxun Zhou's user avatar
Tianxun Zhou
  • 151
1 vote
0 answers
5 views

Prove which of the extended dense linear order models are atomic and saturated

love and light's user avatar
love and light
  • 143
0 votes
0 answers
9 views

Does k dimension simplexes under certain conditions homeomorphism with k+1-sphere

wer's user avatar
wer
  • 417
-1 votes
0 answers
7 views

State Equation for LTI Systems

David Castillo Mejia's user avatar
David Castillo Mejia
  • 1
0 votes
0 answers
6 views

Elliptic Integrals and Jacobean Elliptic functions

pwm's user avatar
pwm
  • 11
0 votes
0 answers
11 views

Variance-Bias Decomposition in Banach Spaces

Syd Amerikaner's user avatar
Syd Amerikaner
  • 517
2 votes
0 answers
21 views

Number of rational points of orthogonal groups

sunkist's user avatar
sunkist
  • 1,093
5 votes
0 answers
40 views

The fabulous Wenger's Summation

Alma Arjuna's user avatar
Alma Arjuna
  • 2,147
1 vote
1 answer
99 views

Prove that restricted to a vertical plane $dx \wedge dy = 0$.

rych's user avatar
rych
  • 4,090
1 vote
0 answers
40 views

$\overline{\mu}(E) = 0$ iff there is $(A_n) \subset \mathscr{A}$ s.t. $E \subset \overline{\lim}_{n \to \infty} A_n$

Blue Tomato's user avatar
Blue Tomato
  • 719
-1 votes
0 answers
57 views

How to prove $P(m) | P(n)$, where $m | n$, where $P(n)$ represents the $n^{\text{th}}$ element in a Fibonacci sequence?

Pavan C.'s user avatar
Pavan C.
  • 1,065
10 votes
1 answer
265 views

The number of the union-intersection calculation results equals to the number of paths

Alexander Burstein's user avatar
Alexander Burstein
  • 3,960
0 votes
0 answers
8 views

Novel Approach to Normal Estimation in Surface Reconstruction

Sterling Butters's user avatar
Sterling Butters
  • 35
0 votes
3 answers
51 views

I want to use integration for performing summation in Algebra

Claude Leibovici's user avatar
Claude Leibovici
  • 255k
0 votes
0 answers
35 views

Show x* = [...] is optimal for a given problem

bikeactuary's user avatar
bikeactuary
  • 113
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