Mathematics Stack Exchange

0

votes

1

answer

9

views

Can we apply Egorov's theorem?

limits measure-theory convergence uniform-convergence

answered 1 min ago user159517 4,161

0

votes

1

answer

23

views

Linear Diophantine Equation Signs

linear-algebra abstract-algebra number-theory diophantine-equations

answered 5 mins ago steven gregory 16.5k

1

vote

1

answer

14

views

Finding the standard deviation of a probability distribution.

probability statistics probability-distributions

answered 7 mins ago Jean-Claude Arbaut 14.2k

1

vote

1

answer

39

views

Inequality in a scalar product.

functional-analysis analysis inequality vectors

modified 8 mins ago user159517 4,161

0

votes

1

answer

18

views

Integrating the geometric series

complex-analysis power-series proof-explanation

answered 9 mins ago marty cohen 69.3k

2

votes

2

answers

38

views

Multidimensional chain rule, online calculator

multivariable-calculus wolfram-alpha online-resources calculator

modified 12 mins ago Somos 11.7k

0

votes

2

answers

16

views

Writing a complex invertible matrix as the product of a real invertible matrix and a complex number.

matrices

modified 12 mins ago csk231 64

0

votes

4

answers

32

views

straight line, the question is- Find where the line joining the points $(-3,5)$ and $(-4,8)$ meets the line $x=15$.

geometry

answered 14 mins ago amd 26k

-1

votes

2

answers

23

views

Integrating a logistic form involving both dependent and independent variables

calculus integration differential-equations

answered 16 mins ago Henry Lee 492

1

vote

1

answer

40

views

Finite difference method for non-linear PDE

pde numerical-methods transport-equation

modified 16 mins ago Harry49 4,746

1

vote

1

answer

27

views

prove for equality with formula using binomial coefficients

binomial-coefficients

modified 18 mins ago matosch 19

2

votes

0

answers

23

views

norm induced by distance implies translation invariant distance?

general-topology metric-spaces

modified 18 mins ago G.Jimenez 95

2

votes

3

answers

43

views

Find $\lim_{x\to 0^+} \int_x^{+\infty} t^{-1}e^{-t}dt/{\ln(1/x)}$

calculus integration limits definite-integrals

modified 19 mins ago Henning Makholm 226k

0

votes

0

answers

10

views

Group cohomology of finite groups with real coefficients vanishes?

finite-groups exact-sequence group-cohomology

asked 24 mins ago Herman Chu 28

1

vote

1

answer

18

views

Let $f\in L^p (R)$ for $1\leq p<\infty$ and let $f_t(x)=f(x-t)$.

measure-theory hilbert-spaces lebesgue-measure

modified 26 mins ago user159517 4,161

2

votes

1

answer

18

views

Tangential quadrilaterals description

geometry euclidean-geometry circle quadrilateral

answered 28 mins ago Aretino 21.8k

0

votes

2

answers

32

views

Understanding closure of a group

abstract-algebra group-theory

modified 30 mins ago Daniel Mroz 931

0

votes

0

answers

13

views

When is the dirac delta function taken as 1 and when it is taken as infinity

dirac-delta

asked 31 mins ago A.J. 118

0

votes

0

answers

4

views

What is the inverse CDF of the EMG distribution?

statistics probability-distributions

asked 33 mins ago J De Leo 1

2

votes

1

answer

180

views

Prove that there is an isomorphism of vector spaces from the tangent space at the identity to the tangent space at any other element of the group

group-theory lie-algebras lie-groups

modified 33 mins ago 许94.94 XU 36

0

votes

2

answers

19

views

Probability theory inequality

probability-theory measure-theory

answered 35 mins ago tmaths 917

2

votes

1

answer

44

views

Smallest $C^*$-subalgebra in tensor product

linear-algebra proof-verification tensor-products c-star-algebras

modified 36 mins ago bdt 26

0

votes

0

answers

12

views

A question related to group cohomology and spectral sequences

homological-algebra exact-sequence group-cohomology spectral-sequences group-extensions

asked 45 mins ago Herman Chu 28

2

votes

0

answers

13

views

Finding the expansion coefficients of the decomposition of a 3D Gaussian wavepacket in the eigenfunctions of the Hydrogen atom

calculus fourier-analysis quantum-mechanics

modified 50 mins ago user3613025 31

1

vote

1

answer

55

views

+50

If $G$ is a LCA, does always exist a discrete subgroup $H$ of $G$ such that $G/H$ is compact?

harmonic-analysis topological-groups

modified 52 mins ago Sheve 76

1

vote

0

answers

54

views

Find recursion rule after n

recursion

modified 53 mins ago amWhy 189k

0

votes

0

answers

10

views

Convergence of $\sum_k^{n-1}f\left(\frac{k+\theta} n\right)-n\int_0^1 f(x)\,dx$ doubt

calculus real-analysis integration

asked 55 mins ago Pedro Gomes 1,319

1

vote

1

answer

25

views

the induced trivial $*$ homomorphism

operator-theory operator-algebras c-star-algebras

answered 57 mins ago André S. 1,567

1

vote

0

answers

19

views

Suppose $f_n\rightarrow f$ Point wise a.e.

measure-theory hilbert-spaces

asked 58 mins ago Areedd 52

0

votes

0

answers

53

views

What's the correct syntax for defining a matrix/tensor via its indices.

matrices notation tensors

modified 1 hour ago spinkus 125

0

votes

0

answers

26

views

Barycentric subdivision in convex sets: is Rotman's definition incorrect?

algebraic-topology barycentric-coordinates

modified 1 hour ago Cave Johnson 3,612

0

votes

0

answers

32

views

integration with angles in spherical coordinates

calculus integration

modified 1 hour ago user58293 6

1

vote

2

answers

16

views

Minimizing total variation with small norm in a compact set

functional-analysis measure-theory bounded-variation geometric-measure-theory total-variation

modified 1 hour ago jJjjJ 364

4

votes

2

answers

42

views

For $x'(t)= f(t, x(t)) + \int_0^t g(x(s))\, ds$ show that if $x_1(0) \leq x_2(0)$ that also $x_1(t) \leq x_2(t)$

calculus real-analysis differential-equations

modified 1 hour ago Darkwizie 140

0

votes

0

answers

13

views

Applying Riesz Representation Theorem to prove $g \in L^{p}(E) = 0$ if integral of $fg$ is 0 for all $f$ in dense subset of $L^{q}(E)$

integration lp-spaces riesz-representation-theorem

asked 1 hour ago BMac 245

1

vote

2

answers

23

views

Probability without replacement - given label chosen third

probability permutations

modified 1 hour ago BruceET 33.3k

2

votes

3

answers

41

views

Difference between the complex plane and cartesian plane

soft-question

answered 1 hour ago Andres Mejia 15.2k

0

votes

0

answers

13

views

If $X$ is a time-homogeneous Markov chain and $p(x,y):=\text P[X_1=y\mid X_0=x]$, then $p^n(x,y)=\text P[X_n=y\mid X_0=x]$

probability probability-theory stochastic-processes markov-chains

asked 1 hour ago 0xbadf00d 2,041

31

votes

3

answers

4k

views

A conjecture involving prime numbers and circles

number-theory algebraic-geometry prime-numbers euclidean-geometry circle

modified 1 hour ago Direwolf202 1

2

votes

1

answer

23

views

How to find the first few terms of the taylor expansion of $\sqrt[5]{t} \int \frac{1}{\sqrt[5]{t}} (1-t)^{-\frac{1}{5}} \, dt$?

calculus

answered 1 hour ago A. Pongrácz 3,309

1

vote

0

answers

39

views

Representing curves using elements of a free group

algebraic-topology homotopy-theory curves free-groups

modified 1 hour ago T.Harish 97

0

votes

1

answer

28

views

I need help with finding a polynomial and using it to find a perimeter

polynomials

modified 1 hour ago Fabio Lucchini 5,694

2

votes

1

answer

28

views

Are Riemannian manifolds only referred to as diffeomorphic if the diffeomorphism is an isometry?

differential-geometry terminology manifolds isometry diffeomorphism

answered 1 hour ago Jack Lee 25.3k

1

vote

1

answer

33

views

Find all prime ideals of $\mathbb{Z} / n\mathbb{Z} \ [x]$

abstract-algebra polynomials ring-theory

answered 1 hour ago Don 136

1

vote

1

answer

10

views

Suppose $\mu$ and $\nu$ are finite positive measures on a measuable space

measure-theory hilbert-spaces

answered 1 hour ago A. Pongrácz 3,309

0

votes

0

answers

15

views

Optimization using Hungarian Algorithm

optimization

asked 1 hour ago leutsoa moteka 1

3

votes

2

answers

41

views

Given orthogonal vibrations, how can I find the magnitude and direction of the major axis of the resulting ellipse?

geometry trigonometry conic-sections parametric

modified 1 hour ago amd 26k

0

votes

1

answer

14

views

Computing the transformation of a plane $\eta_1$ to another plane $\eta_2$

linear-algebra euclidean-geometry transformation rotations

modified 1 hour ago amd 26k

0

votes

1

answer

27

views

Calculation of confidence interval for population mean if population not normally distributed

statistics normal-distribution means central-limit-theorem

modified 1 hour ago Don Fuchs 25

2

votes

1

answer

29

views

Clustering Coefficient: Apparent in the Characteristic Polynomial?

linear-algebra graph-theory algebraic-graph-theory network

answered 1 hour ago Vladimir Stozhkov 113

0

votes

0

answers

8

views

What is the correct way to obtain the position of a quartile and its value?

statistics

asked 2 hours ago Mattiu 6

1

vote

1

answer

34

views

Torsion Coefficient in Group Theory

abstract-algebra group-theory abelian-groups direct-product torsion-groups

modified 2 hours ago Misha Lavrov 35.7k

1

vote

1

answer

28

views

discrete multiplicative subgroup of the reals are cyclic

group-theory algebraic-number-theory absolute-value valuation-theory

modified 2 hours ago Michael Hardy 204k

0

votes

0

answers

12

views

Calculating the influence of changing volumes and values on a single average

analysis

modified 2 hours ago Mathsmaths 1

3

votes

1

answer

34

views

Convergence of$\int_{0}^{+\infty}\frac{1}{\left(\log(x)\right)^{4\alpha}}\sin^2\left(\frac{1}{x^{\alpha}}\right)\,dx$

real-analysis improper-integrals

answered 2 hours ago Olivier Oloa 106k

0

votes

0

answers

6

views

Criteria for creating cumulative frequency and cumulative relative frequency table

statistics

asked 2 hours ago Mattiu 780

1

vote

0

answers

18

views

How to use the joint distribution of X,Y for the distribution of X+Y with unknown dependency structure

probability-distributions

modified 2 hours ago md2perpe 6,025

2

votes

1

answer

37

views

What explains this feature of measurable cardinals?

set-theory cardinals

answered 2 hours ago Asaf Karagila♦ 292k

1

vote

0

answers

43

views

+100

Alternative way of calculating the intersection number on a surface

algebraic-geometry surfaces schemes intersection-theory

modified 2 hours ago manifold 233

1

vote

1

answer

15

views

Convergence to zero in total variation: Seeking a contradiction

functional-analysis measure-theory bounded-variation geometric-measure-theory total-variation

answered 2 hours ago user357151 13.9k

0

votes

0

answers

31

views

Need help with this SEA Math Competition question! Geometry

geometry triangle problem-solving

asked 2 hours ago fluxx1240 1

1

vote

1

answer

23

views

On proving that if a commuting rectangle's right and outer square are pullbacks, then so is the left square.

proof-writing category-theory

answered 2 hours ago Guido A. 3,851

2

votes

1

answer

10

views

Question About Divisors Of Coloring Polygons

combinatorics coloring

answered 2 hours ago Misha Lavrov 35.7k

4

votes

5

answers

140

views

Non-constant infinite arithmetic progressions?

problem-solving integers arithmetic-progressions

answered 2 hours ago Agnishom Chattopadhyay 44

3

votes

1

answer

88

views

Deciding whether the maximal ideal $\mathfrak{m}R_\mathfrak{m}$ is generated by two elements

abstract-algebra algebraic-geometry ring-theory commutative-algebra localization

answered 2 hours ago xarles 1,084

3

votes

1

answer

22

views

Analogues of the elementary symmetric polynomials for the alternating group

polynomials permutations symmetric-polynomials

answered 2 hours ago alphacapture 1,777

1

vote

0

answers

15

views

Proving maximum of $u$ on $\overline\Omega$ is achieved on $\partial \Omega$ using $Lv = \sum a_{jk}\partial_{jk} + \sum b_j(x)\partial_j$

calculus multivariable-calculus pde surfaces maxima-minima

asked 2 hours ago Guerlando OCs 491

0

votes

0

answers

25

views

Injective differential of linear operators on a Hilbert space

matrices derivatives manifolds

modified 2 hours ago Alpha001 103

2

votes

1

answer

24

views

Maximum likelihood estimate for 2 coins.

probability maximum-likelihood

answered 2 hours ago heropup 59.8k

3

votes

1

answer

51

views

About $f:[0,1]\rightarrow \mathbb{R}$ integrable with $f \geq 0$, and $A_{t}=\{x\in [0,1]\mid t \leq f(x) \leq 2t\}$

real-analysis measure-theory lebesgue-integral

answered 2 hours ago user159517 4,161

0

votes

1

answer

48

views

Placing $n$ linear functions so that it is best fit to another function in integral norm sense?

calculus real-analysis optimization linear-approximation

modified 2 hours ago mathreadler 13.6k

0

votes

0

answers

29

views

Solving underdetermined linear system using least squares

linear-algebra convex-analysis convex-optimization least-squares quadratic-programming

modified 2 hours ago Rodrigo de Azevedo 12.6k

2

votes

0

answers

53

views

Minimal sufficient statistic for $\theta$ where $f(x;\theta)=\frac{\beta^3}{2}e^{-\beta(x-\theta)}(x-\theta)^2\mathbf1_{x\ge\theta}$

statistics data-sufficiency

modified 2 hours ago Michael Hardy 204k

0

votes

0

answers

10

views

Determining a polyhedron from a series of inequalities

linear-algebra optimization polyhedra

asked 2 hours ago TestGuest 388

27

votes

5

answers

7k

views

How does Cramer's rule work?

linear-algebra matrices systems-of-equations determinant

answered 2 hours ago Rodrigo de Azevedo 12.6k

0

votes

2

answers

1k

views

Find the orthogonal projection of a vector v onto U

linear-algebra vectors transpose

modified 2 hours ago Community♦ 1

4

votes

1

answer

43

views

Asymptotic relation between $\Phi(x,z)$ and $\Psi(x,z)$

number-theory elementary-number-theory prime-numbers analytic-number-theory sieve-theory

answered 3 hours ago Daniel Fischer♦ 171k

0

votes

0

answers

23

views

Let $A\in M_{m\times n}(\mathbb{R})$ be of rank $m$. Choose the correct statement(s) from below:

linear-algebra matrices

modified 3 hours ago Cornman 2,591

2

votes

0

answers

15

views

Is there an equivalence between subgradient and stochastic gradient?

optimization convex-optimization machine-learning numerical-optimization subgradient

modified 3 hours ago Rodrigo de Azevedo 12.6k

2

votes

1

answer

27

views

Showing that a polynomial is zero given that a sum containing its coefficients sum to zero

real-analysis polynomials

modified 3 hours ago Cornman 2,591

0

votes

0

answers

14

views

Ring of partitions and degree of a divisor

algebraic-geometry divisors-algebraic-geometry

asked 3 hours ago Hypertrooper 69

3

votes

1

answer

33

views

Differentials of non-smooth functions, wedge products of currents?

differential-geometry distribution-theory differential-forms foliations

modified 3 hours ago Ted Shifrin 59.6k

0

votes

0

answers

16

views

Decompose a parametric curve into monotone segments

calculus geometry differential-geometry numerical-methods

modified 3 hours ago plasmacel 385

5

votes

1

answer

72

views

If every functional of $f$ is smooth, is $f$ smooth?

analysis functional-analysis

answered 3 hours ago barto 13k

4

votes

1

answer

100

views

Don't follow proof that Hadamard differentiable implies compactly differentiable

functional-analysis derivatives banach-spaces gateaux-derivative

answered 3 hours ago Eric Wofsey 163k

0

votes

0

answers

7

views

The relationship between spectral decomposition / eigendecomposition and projection operators

eigenvalues-eigenvectors matrix-decomposition projection-matrices

modified 3 hours ago AnInquiringMind 103

0

votes

0

answers

11

views

Plot the graph of the square wave function defined as $f(t)=\sum^{\infty}_{n=0}(-1)^n h_{n}(t)$ on the interval $t>0$ and find its Laplace transform.

calculus derivatives fourier-series graphing-functions fourier-transform

asked 3 hours ago Mike 770

4

votes

0

answers

37

views

Binomial Coefficients involving Prime Powers minus 1

number-theory summation prime-numbers binomial-coefficients research

modified 4 hours ago Lalaloopsy 1,194

0

votes

0

answers

6

views

P.r. Properties, Computability, Arithmetic

first-order-logic recursion computability

asked 4 hours ago Fablez 1

0

votes

0

answers

15

views

Derivation of formula to calculate the angle of inclination

linear-algebra geometry proof-explanation

asked 4 hours ago Pratham Gandhi 1

1

vote

0

answers

15

views

Structure satisfiability and entailment

logic first-order-logic predicate-logic

asked 4 hours ago Eloo 79

0

votes

3

answers

40

views

Where do we use continuity?

calculus real-analysis derivatives continuity data-sufficiency

answered 4 hours ago xbh 1,597

2

votes

0

answers

30

views

Generating function for the number of unlabeled trees on $n$ vertices

sequences-and-series combinatorics graph-theory generating-functions trees

asked 4 hours ago Bumblebee 9,403

0

votes

0

answers

23

views

Probability of a series of events which may be recursive

probability statistics

asked 4 hours ago P591 1

1

vote

2

answers

1k

views

Prove that $\arcsin z = \frac{\pi}{2} - \arccos z$

complex-analysis

modified 4 hours ago Community♦ 1

4

votes

0

answers

17

views

Role of the weight matrix $M$ in $x^T M u$ in the LQR cost function

optimization calculus-of-variations control-theory optimal-control dynamic-programming

modified 6 hours ago Rodrigo de Azevedo 12.6k

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