Mathematics Stack Exchange

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4

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What is the order of $\bar{2}$ in the multiplicative group $\mathbb{Z}_{221}^\text{x}$?

abstract-algebra multiplicative-order

asked 1 min ago B24Panther 51

2

votes

1

answer

60

views

+50

Convolution of a function and its Fourier transform

fourier-analysis fourier-transform convolution

modified 1 min ago Cameron 283

0

votes

0

answers

2

views

Economics-utility function

functions economics monotone-functions utility

asked 2 mins ago Lifeni 161

0

votes

0

answers

3

views

Poisson Processes Equation

probability

asked 2 mins ago M Kaneki 1

0

votes

0

answers

27

views

Show that $(2^{47}*3^{100})$ is divisible by 43 .

discrete-mathematics prime-numbers modular-arithmetic divisibility

modified 2 mins ago John 43

1

vote

2

answers

15

views

How to prove $a \ln(b) \sqrt{b} > b \ln(a) \sqrt{a}$ for $a,b > 0$ and $a>b$

inequality proof-writing

modified 2 mins ago Michelle 844

0

votes

0

answers

6

views

Two different solutions to an integral

calculus logarithms

asked 3 mins ago hur 13

0

votes

0

answers

5

views

How can I show that the second derivative of $f(x)= \sum_{n=1}^\infty \frac{1}{x^4+n^4}$ exists?

real-analysis functional-analysis derivatives uniform-convergence sequence-of-function

asked 3 mins ago david harun 119

0

votes

0

answers

6

views

Is it true that the dimension of an eigenspace of a square matrix is at most the multiplicity of the corresponding eigenvalue?

linear-algebra eigenvalues-eigenvectors

asked 4 mins ago Lapin 1

0

votes

0

answers

3

views

Understanding submanifolds of $\mathbb{R}^{2 \times 2}$

linear-algebra differential-geometry algebraic-geometry algebraic-topology submanifold

asked 4 mins ago Tristan Duquesne 422

0

votes

0

answers

3

views

Spectrum of fourier transform of $\delta(t-t_0)$

fourier-analysis fourier-transform dirac-delta

asked 5 mins ago Denny 563

0

votes

0

answers

4

views

Expectation of correlated random variables

statistics random-variables expected-value correlation

asked 6 mins ago Selos 75

1

vote

1

answer

10

views

Find all sets of integers (a,b,c) with $a>0>b>c$, which have as a sum 0 and the number $N=2017-a^3b-b^3c-c^3a$ is a perfect square

number-theory prime-numbers contest-math problem-solving integers

modified 6 mins ago Hagen von Eitzen 331k

0

votes

0

answers

5

views

General formula for derivative of multiplication

derivatives numerical-methods

asked 7 mins ago nikberX 23

0

votes

1

answer

8

views

Find an appropriate transformation

calculus ordinary-differential-equations boundary-value-problem

modified 7 mins ago Sewer Keeper 1,326

1

vote

1

answer

18

views

Multiplication operator with fixed continuous function

functional-analysis hilbert-spaces lp-spaces

modified 9 mins ago Matematleta 23.3k

0

votes

0

answers

6

views

The variance of in Brownian motion

probability normal-distribution brownian-motion

asked 9 mins ago Tim 337

1

vote

0

answers

9

views

How to prove this inequality on trace of inverse of a positive definite matrix?

matrices inequality inverse trace positive-definite

modified 9 mins ago epimorphic 3,104

0

votes

1

answer

10

views

Two commuting weights in a von Neumann algebra

operator-algebras c-star-algebras von-neumann-algebras

answered 9 mins ago Martin Argerami 158k

0

votes

1

answer

4

views

Help approximating the leading eigenvalue of this Jacobian

ordinary-differential-equations eigenvalues-eigenvectors stability-in-odes jacobian

answered 11 mins ago Robert Israel 394k

0

votes

1

answer

13

views

Definition of a centralizer of a weight

operator-algebras c-star-algebras von-neumann-algebras

answered 12 mins ago Martin Argerami 158k

0

votes

0

answers

10

views

Proving that set of statements and assigns is not empty

logic

asked 13 mins ago vesii 1,339

2

votes

1

answer

10

views

Proving that Geometric Brownian Motion is positive

stochastic-processes stochastic-calculus brownian-motion finance stochastic-differential-equations

answered 14 mins ago user6247850 1,984

1

vote

2

answers

27

views

How to solve a quadratic equation with floor function

calculus number-theory ceiling-and-floor-functions

modified 17 mins ago Raffaele 18.7k

0

votes

1

answer

31

views

Is my limit proof ok? , with $f(x)^2$

limits solution-verification epsilon-delta

answered 17 mins ago WA Don 2,186

-1

votes

0

answers

7

views

Consider the sequences and choose the correct options

real-analysis

asked 18 mins ago KULDEEP SARMA 1

0

votes

0

answers

11

views

Lebesgue points of a set

measure-theory

modified 18 mins ago David C. Ullrich 76.9k

1

vote

1

answer

9

views

Combinatorics with repetition - is my textbook right?

combinatorics

answered 17 secs ago N. F. Taussig 57.8k

0

votes

0

answers

2

views

Prove that $ \Delta = (a + \bar{a} - 2)^2$ with (E) : $z^2-2(a-\bar{a})z - |a-1|^2$ in ${\displaystyle \mathbb {C} }$

complex-numbers

asked 18 mins ago Malek Gara-Hellal 13

0

votes

0

answers

6

views

Description of a set in the Baire space.

real-analysis metric-spaces the-baire-space

asked 18 mins ago Haus 565

0

votes

0

answers

3

views

Is a subset of stationary process is stationary process?

stochastic-processes covariance stationary-processes

asked 19 mins ago Bruh 449

0

votes

0

answers

6

views

Examine the convergence of the following integrals:

integration convergence-divergence

asked 20 mins ago Qcc 1

1

vote

1

answer

16

views

Monte carlo methods and the curse of dimensionality for solving PDEs

partial-differential-equations numerical-methods monte-carlo

answered 21 mins ago Robert Israel 394k

0

votes

1

answer

14

views

On Supremuma and limits

real-analysis continuity solution-verification supremum-and-infimum

answered 21 mins ago Sam Wong 894

0

votes

0

answers

13

views

A difficulty with Fourier sine transform

complex-analysis fourier-analysis fourier-transform

modified 21 mins ago Bernard 158k

1

vote

0

answers

12

views

Which of the following options are correct about $X = \left \{C \in GL_3 (\Bbb R)\ |\ CAC^{-1}\ \text {is triangular} \right \}\ $?

linear-algebra matrices diagonalization jordan-normal-form triangularization

asked 28 mins ago Phi beta kappa 586

0

votes

0

answers

5

views

What's the probability for two planar squares in 3D with fixed centers of both being horizontal and with one of their sides facing the other?

probability geometry 3d

asked 28 mins ago Sebasen 135

-1

votes

0

answers

14

views

Convergence/ Divergence of improper trigonometric integral $ \int_0^{\infty}\frac{\tan x}{x}\mathrm dx $

convergence-divergence improper-integrals

asked 29 mins ago Delight 21

0

votes

0

answers

5

views

Is there a “canonical” (probability) measure on continuous functions?

probability functional-analysis measure-theory wiener-measure

modified 29 mins ago Riccardo Ceccon 1,318

0

votes

1

answer

26

views

Number of ways to express $n$ as a sum of squares of integers

combinatorics elementary-number-theory natural-numbers

answered 30 mins ago saulspatz 39.3k

0

votes

1

answer

13

views

Every path-connected covering $X\to\Bbb S^1\lor\Bbb S^1$ with $\pi_1(X)$ non-trivial abelian, is irregular

algebraic-topology solution-verification trees covering-spaces fundamental-groups

modified 30 mins ago Lee Mosher 77.1k

0

votes

0

answers

4

views

Hungarian Algorithm: Sequence of Choices

optimization operations-research bipartite-graphs matching-theory

asked 30 mins ago ABC 101

1

vote

0

answers

44

views

What is the intuition behind Picard's existence and uniqueness theorem

ordinary-differential-equations

modified 30 mins ago at-in 242

0

votes

0

answers

3

views

Singular value decomposition summation matrices

svd singular-values

modified 31 mins ago Streamline Astra 15

0

votes

0

answers

6

views

General approach of pricing an European option with specific payoff & instance

stochastic-calculus finance stochastic-pde

modified 34 mins ago kallikles 29

1

vote

0

answers

9

views

Proving degree bounds for $u, v$ in $c = ua + vb$ (Bezout's identity generalisation)

abstract-algebra polynomials algorithms factoring gcd-and-lcm

modified 34 mins ago Linear Christmas 920

-1

votes

1

answer

29

views

Cardinality of $S = \{f: \{\sqrt{11}, \sqrt{13}\} \mapsto \mathbb{Q} \}$?

elementary-number-theory

modified 34 mins ago Kyle McDonald 1

0

votes

0

answers

13

views

Combinatorics problem - 15 police officers uses the services of 5 secretaries.

combinatorics discrete-mathematics proof-writing

asked 35 mins ago Theodor Todorov 11

0

votes

0

answers

5

views

Midpoints on Riemannian manifold with bounded curvature

riemannian-geometry curvature

asked 36 mins ago TrivialPursuit 141

0

votes

0

answers

5

views

Relation between $R^2$ and t-statistics

statistics regression

asked 37 mins ago Kaan Yolsever 424

0

votes

0

answers

19

views

Geometry problem : Incircle and Menelaus

geometry euclidean-geometry

modified 39 mins ago Mathematical Curiosity 859

0

votes

0

answers

10

views

Question on expectation found in a proof - it seems there is a mistake?

probability probability-distributions random-variables expected-value

asked 39 mins ago sonicboom 8,299

1

vote

0

answers

9

views

Divergence of the gaussian hypergeometric function 2F1

complex-analysis convergence-divergence

asked 40 mins ago Ivan Girona 11

0

votes

0

answers

4

views

Constructing a Lyapunov function for an ODE system that describes epidemic spreading on scale-free networks

ordinary-differential-equations nonlinear-system lyapunov-functions

asked 43 mins ago YHH 534

1

vote

0

answers

9

views

The Ricci form and the Chern class?

differential-geometry complex-geometry curvature characteristic-classes kahler-manifolds

asked 44 mins ago LSY 515

0

votes

1

answer

11

views

Dijkstra Algorithm recovery from long dead ends behaviour

graph-theory algorithms

modified 46 mins ago toronto hrb 573

0

votes

1

answer

11

views

Find the axis of reflection which is described a matrix

linear-algebra matrices eigenvalues-eigenvectors

modified 47 mins ago El Hayes 36

0

votes

0

answers

31

views

Reference Request: Factored Polynomials with Negative Integer Zeros and Divisor-Related Multiplicities

sequences-and-series algebra-precalculus polynomials reference-request ceiling-and-floor-functions

modified 48 mins ago Eleven-Eleven 8,059

1

vote

0

answers

17

views

Why isn't the Fourier transform self-inverse?

fourier-analysis abelian-groups duality-theorems locally-compact-groups

asked 52 mins ago user357269 467

0

votes

0

answers

5

views

Finding expectations values of stochastic integrals.

stochastic-calculus stochastic-integrals

modified 52 mins ago Hariboharry 1

-1

votes

0

answers

8

views

Union of three events when C is a subset of B

probability

asked 52 mins ago octavemirbeau 1

2

votes

1

answer

2k

views

Examples where constant step-size gradient descent fails everywhere?

optimization numerical-optimization gradient-descent

modified 53 mins ago Rodrigo de Azevedo 16.4k

2

votes

1

answer

25

views

$f$ meromorphic prove that $f$ is not constant

complex-analysis solution-verification mobius-transformation meromorphic-functions

answered 54 mins ago Caffeine 4,724

0

votes

0

answers

3

views

why we need left invariance to defines integral on lie groups

integration lie-groups

asked 54 mins ago amilton moreira 191

0

votes

1

answer

18

views

Determine the set of positions of $ M$

complex-numbers

answered 54 mins ago Raffaele 18.7k

1

vote

0

answers

7

views

Lipschitz property of the coefficients of the averaged equation in Khaminskii's case

stochastic-processes stochastic-calculus stochastic-analysis stochastic-differential-equations stochastic-pde

modified 54 mins ago defex95 23

0

votes

0

answers

4

views

Find scale, rotation, and translation that maps three points to three points in 3D

linear-algebra linear-transformations

asked 55 mins ago wcochran 448

0

votes

0

answers

10

views

Cancellation property in internal direct product of groups

abstract-algebra group-theory

asked 56 mins ago carciofo21 169

4

votes

3

answers

67

views

If$ |G|=pq $ and $p $ doesnt divide $(q-1)$ and $p <q$ then $G$ is cyclic.

abstract-algebra group-theory

modified 59 mins ago Jyrki Lahtonen 117k

-1

votes

0

answers

12

views

Ferris Wheel Trig Question - 2nd revolution

functions trigonometry word-problem

modified 1 hour ago GNUSupporter 8964民主女神地下教會 15.1k

-2

votes

0

answers

15

views

Gaussian elimination for $A=LR$ form matrix to compute inverse of $L$

gaussian-elimination

modified 1 hour ago Parcly Taxel 70.9k

-1

votes

0

answers

4

views

How to calculate subgradient of polyhedral projection mapping?

real-analysis convex-analysis

asked 1 hour ago Kuangyu Ding 1

0

votes

0

answers

11

views

distribution of linearly transformed variable

probability probability-theory measure-theory probability-distributions random-variables

asked 1 hour ago LrM 59

0

votes

0

answers

15

views

Is $E\bigg[\dfrac{1}{1_{X \in [a,b]}} f(X)\bigg]$ finite?

probability probability-distributions random-variables expected-value

modified 1 hour ago sonicboom 8,299

3

votes

0

answers

17

views

+100

Cube of stationary variable

stochastic-processes stochastic-analysis stationary-processes

modified 1 hour ago Denezio 10

1

vote

0

answers

17

views

A question about floor functions and series.

number-theory elementary-number-theory inequality radicals ceiling-and-floor-functions

asked 1 hour ago Aditya_math 386

0

votes

0

answers

10

views

Prove the irreducibility of $f(X,Y)$

linear-algebra abstract-algebra polynomials irreducible-polynomials

modified 1 hour ago FFjet 1,351

0

votes

0

answers

6

views

Non-empty intersection of infinitly many subsets in Finite measure space

measure-theory

asked 1 hour ago Mike1234 1

1

vote

1

answer

11

views

definition of “edge disjoint union” in graph theory

graph-theory definition

modified 1 hour ago ArsenBerk 10.9k

0

votes

2

answers

22

views

Estimate of $\frac{\cosh^2(x)}{\sinh^2(x)}-\frac{\cosh^2(y)}{\sinh^2(y)}$ depending on $x$ and $y$

real-analysis analysis maxima-minima upper-lower-bounds

answered 1 hour ago Claude Leibovici 172k

0

votes

0

answers

5

views

Supremum and Expectation

probability probability-theory measure-theory

modified 1 hour ago Kaira 340

0

votes

0

answers

7

views

Does the function $ \frac{e^{-2x}-1}{(q-1)e^{-2x}+1}$ have a name and what properties does it share with $\tanh(x)$?

functions reference-request statistical-mechanics

asked 1 hour ago Frederik Ravn Klausen 300

0

votes

0

answers

8

views

Reference for another equivalent of Riemann hypothesis

number-theory analytic-number-theory riemann-hypothesis

asked 1 hour ago Ahmad 2,830

1

vote

0

answers

8

views

Importance sampling - statistics

statistics statistical-inference statistical-mechanics estimator

asked 1 hour ago vislty 11

0

votes

0

answers

12

views

Common part of two systems of linear equations modulo 2

linear-algebra

modified 1 hour ago d3m4nz3 179

0

votes

0

answers

4

views

Are SU(n) invariants necessarily non-commuting?

lie-groups lie-algebras invariant-theory

asked 1 hour ago zooby 3,431

0

votes

0

answers

3

views

Action by conjugation, orbits and isotropy groups

lie-groups smooth-manifolds

asked 1 hour ago Toy 1

3

votes

1

answer

13

views

If $H$ is a compact object then is true that $H\simeq H_{\alpha_0}$ for some $\alpha_0$?

category-theory

answered 1 hour ago Kevin Arlin 42.9k

0

votes

0

answers

11

views

Laplace transform of Gaussian density function times the error function

calculus integration probability-distributions laplace-transform gaussian-integral

modified 1 hour ago Seyhmus Güngören 7,214

0

votes

0

answers

32

views

+100

Invariant superoperators under unitary action

functional-analysis group-theory representation-theory hilbert-spaces tensor-products

modified 1 hour ago backstrapp 205

0

votes

0

answers

9

views

Is there a simpler way to prove that a fractional function with three variables is convex?

proof-writing convex-analysis convex-optimization hessian-matrix jensen-inequality

asked 2 hours ago shsh 33

0

votes

1

answer

35

views

Fundamental Forms and Connect Forms Question

calculus differential-geometry

modified 2 hours ago Nono4271 69

0

votes

0

answers

9

views

$\limsup$ for the sum of random variables

probability random-variables limsup-and-liminf

asked 2 hours ago Joris Wk 165

1

vote

0

answers

12

views

Cauchy-Riemann Equations on disconnected open set

complex-analysis

asked 2 hours ago boaz 3,470

2

votes

0

answers

19

views

Changing order of integration in infinite-dimensional space

functional-analysis fubini-tonelli-theorems

asked 2 hours ago user5211657 21

5

votes

0

answers

25

views

Does almost sure convergence and $L^1$-convergence imply almost sure convergence of the conditional expectation?

probability-theory convergence-divergence random-variables conditional-expectation

modified 2 hours ago Jendrik Stelzner 9,986

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