Mathematics

71%

+3 −0

Besov or Triebel-Lizorkin spaces versus Lorentz spaces

0 answers · posted 2mo ago by LL 3.14‭ · edited 2mo ago by LL 3.14‭

interpolation Besov-space functional-analysis

50%

+1 −1

Prove that $\forall x\in\Bbb R:\lfloor x^2\rfloor-\lfloor rx\rfloor\ge-1\iff|r|\le2$.

1 answer · posted 21d ago by TheCodidacter, or rather ACodidacter‭ · last activity 19d ago by Derek Elkins‭

inequality solution-verification

66%

+2 −0

A program which could derive theorems given formation rules in any modal logic?

1 answer · posted 3mo ago by Julius H.‭ · edited 2mo ago by Peter Taylor‭

computational-mathematics proof-assistants

66%

+2 −0

Using convexity in the proof of Hölder’s inequality

1 answer · posted 3mo ago by Snoopy‭ · last activity 22d ago by Snoopy‭

real-analysis

66%

+2 −0

Concrete examples of set theorists thinking independence proofs only determine provability rather than that a statement is neither true nor false?

1 answer · posted 3mo ago by Julius H.‭ · last activity 2mo ago by Peter Taylor‭

set-theory

28%

+0 −3

What is a dual object? [closed]

0 answers · posted 2mo ago by Julius H.‭ · closed 2mo ago by Peter Taylor‭

category-theory

37%

+1 −3

Are these introductory logic textbooks wrong to teach ‘unless’ = ‘or’? [duplicate]

0 answers · posted 3mo ago by 8500 Ward‭ · closed as duplicate 3mo ago by Peter Taylor‭

logic

62%

+3 −1

Minimal non-standard number in non-standard models of PA

1 answer · posted 2mo ago by Aditya‭ · edited 2mo ago by The Amplitwist‭

logic model peano-arithmetic nonstandard-models

66%

+2 −0

The derivatives of a function at a boundary point

1 answer · posted 3mo ago by tommi‭ · last activity 3mo ago by Snoopy‭

derivatives real-analysis

60%

+1 −0

Why is $ \int_0^{\infty}\left|\frac{\sin x}{x}\right|\ dx=\infty$?

1 answer · posted 4mo ago by Snoopy‭ · last activity 4mo ago by Snoopy‭

real-analysis improper-integral

66%

+2 −0

matrix inverse of $I + A$ where $A$ is skew-symmetric

1 answer · posted 2mo ago by Trevor‭ · last activity 2mo ago by Trevor‭

linear-algebra

71%

+3 −0

Is there a $(n_3)$ configuration which is not self-dual?

1 answer · posted 4mo ago by WheatWizard‭ · last activity 4mo ago by Peter Taylor‭

combinatorics

66%

+2 −0

$\sup(A\cdot B) = (\sup A)(\sup B)$ where $A$ and $B$ bounded sets of positive real numbers

3 answers · posted 4mo ago by Snoopy‭ · edited 4mo ago by Snoopy‭

real-analysis supremum-infimum

50%

+0 −0

Calculation of limit

0 answers · posted 6mo ago by Klein Moretti‭

calculus analysis limits applied-mathematics

44%

+2 −3

Cyclical or “loop” fractals?

1 answer · posted 3mo ago by Julius H.‭ · last activity 3mo ago by r~~‭

real-analysis fractal

40%

+0 −1

While pictorializing $|x - y| < |x + y|$, how can 1 picture simultaneously prove (Reverse) △ Inequalities, $|x-y| ≤ |x|+|y|, |x|-|y| ≤ |x-y|$? [duplicate]

0 answers · posted 7mo ago by Tortilla‭ · closed as duplicate 7mo ago by Peter Taylor‭

visualization

60%

+1 −0

Obtaining the semantics of simple type theory as a particular case of the set-theoretic semantics of dependent type theory

0 answers · posted 5d ago by user205‭ · edited 5d ago by user205‭

constructive-logic type-theory logic

25%

+0 −4

What are the Peano axioms?

1 answer · posted 2mo ago by Julius H.‭ · last activity 2mo ago by rmf‭

logic

71%

+3 −0

Is there a $\Delta$-complex structure on the sphere with less than three $0$-simplices?

1 answer · posted 12d ago by The Amplitwist‭ · last activity 7d ago by Derek Elkins‭

algebraic-topology delta-complex

50%

+1 −1

Explain derived categories to someone without a strong background in homological algebra [closed]

0 answers · posted 2mo ago by Julius H.‭ · closed 2mo ago by Peter Taylor‭

category-theory

28%

+0 −3

What is a “first-order substructural logic that has a cut-free sequent calculus”?

1 answer · posted 2mo ago by Julius H.‭ · last activity 2mo ago by Dan Doel‭

logic

71%

+3 −0

Is there a quadratic version of exponential smoothing?

0 answers · posted 9mo ago by peterbalch‭

statistics signal-processing

66%

+2 −0

The Fourier transform of $1/p^3$

1 answer · posted 2mo ago by C-T‭ · last activity 2mo ago by LL 3.14‭

complex-analysis calculus multivariable-calculus integration fourier-analysis

75%

+4 −0

Is there a statistical method to identify the type of outliers shown in the pictures attached to my question?

1 answer · posted 10mo ago by Ivan Nepomnyashchikh‭ · last activity 5mo ago by Agent Smith‭

statistics

60%

+1 −0

How do I unambiguously define the facial circuits in a $2$-cell embedding of a graph into a surface?

0 answers · posted 9d ago by The Amplitwist‭ · edited 6d ago by The Amplitwist‭

topology graph-theory

66%

+2 −0

For any real number $m$, $ \left|\sum_{n=1}^{\infty}\frac{m}{n^2+m^2}\right|<\frac{\pi}{2} $

1 answer · posted 3mo ago by Snoopy‭ · last activity 3mo ago by Snoopy‭

calculus real-analysis

77%

+5 −0

Finding a single row of Matrix after exponentiation

1 answer · posted 11mo ago by theabbie‭ · edited 11mo ago by trichoplax‭

exponent algorithm matrices

60%

+1 −0

Why does the method of separating variables work?

0 answers · posted 1mo ago by The Amplitwist‭

partial-differential-equations separation-of-variables

33%

+1 −4

How to decide whether to buy a lottery with a too negative EV, but passable $\Pr($you win jackpot at least once│n plays)? [closed]

0 answers · posted 9mo ago by Chgg Clou‭ · edited 9mo ago by Chgg Clou‭

lottery

50%

+0 −0

The effect of measurement accuracy and rounding on hypothesis testing

0 answers · posted 4d ago by tommi‭ · edited 3d ago by tommi‭

statistics hypothesis-testing rounding

60%

+1 −0

What does it mean by saying that $C([0,1])$ is a subset of $L^\infty([0,1])$?

1 answer · posted 4mo ago by Snoopy‭ · last activity 4mo ago by Snoopy‭

real-analysis

25%

+0 −4

How can I improve contrast of red and green, to prove Reverse Triangle Inequality?

1 answer · posted 7mo ago by Tortilla‭ · last activity 7mo ago by Peter Taylor‭

visualization

66%

+2 −0

Does {7,4|3} have a realization on the Klein quartic?

0 answers · posted 1mo ago by WheatWizard‭

polytopes algebraic-geometry

22%

+0 −5

How can school children intuit why over 100, D is larger? But under 100, D% is larger?

2 answers · posted 1y ago by Chgg Clou‭ · last activity 5mo ago by Agent Smith‭

high-school-mathematics

71%

+3 −0

Is it possible to show that a normalised random variable has zero mean and unit variance?

0 answers · posted 7mo ago by mr Tsjolder‭ · edited 7mo ago by mr Tsjolder‭

statistics expectation

71%

+3 −0

What is an example of a pathological imbedding of a(n allowed) graph into an oriented surface?

0 answers · posted 2mo ago by The Amplitwist‭ · edited 2mo ago by The Amplitwist‭

topology graph-theory

50%

+3 −3

Defining Bayes’s theorem from scratch in ZFC

1 answer · posted 3mo ago by Julius H.‭ · last activity 19d ago by xamidi‭

set-theory zfc bayes-theorem

60%

+1 −0

$\liminf (a_n+b_n) = \liminf(a_n)+\liminf(b_n)$ provided that $\lim a_n$ exists

1 answer · posted 4mo ago by Snoopy‭ · edited 4mo ago by Snoopy‭

real-analysis

66%

+2 −0

On Tarski-style universes in type theory

1 answer · posted 1y ago by user205‭ · last activity 1y ago by Derek Elkins‭

type-theory logic

42%

+1 −2

Picture proof for expansion of $x^n−y^n$

2 answers · posted 8mo ago by Este‭ · last activity 8mo ago by Peter Taylor‭

visualization

55%

+3 −2

Intuitively, why doesn't picking unpopular integers ($> 31$) lower your probability of winning lotteries?

1 answer · posted 9mo ago by Ethen‭ · last activity 9mo ago by Derek Elkins‭

lottery

66%

+4 −1

is arithmetic finitely consistent?

0 answers · posted 2mo ago by Jason‭

proof logic peano-arithmetic incompletness consistency

22%

+0 −5

How to intuit that if you destroy someone else's lottery ticket, you didn't deprive her of a chance of winning the lottery?

0 answers · posted 12mo ago by DNB‭ · edited 12mo ago by DNB‭

lottery

37%

+1 −3

Solely by eye, how can 16 year olds visually distinguish $\color{red}{\vec{b} - \vec{r}}$ from $\color{limegreen}{|\vec{b}| - |\vec{r}|}$ ?

2 answers · posted 7mo ago by Tortilla‭ · last activity 7mo ago by Olin Lathrop‭

visualization

71%

+3 −0

If both $\lim_{x\to\infty}f(x)$ and $\lim_{x\to\infty}f'(x)$ exist, then $\lim_{x\to\infty}f'(x)=0$.

1 answer · posted 3mo ago by Snoopy‭ · last activity 3mo ago by Snoopy‭

real-analysis

50%

+0 −0

Universal property of quotient spaces

2 answers · posted 1y ago by Snoopy‭ · last activity 12mo ago by ronno‭

topology

33%

+0 −2

2 construals "of 100 patients presenting with a lump like the claimant’s in Gregg v Scott, 42 will be ‘cured’ if they are treated immediately."

2 answers · posted 12mo ago by DNB‭ · last activity 12mo ago by r~~‭

statistics

71%

+3 −0

Classification for involutory real infinite series

1 answer · posted 9mo ago by nsajko‭ · last activity 8mo ago by Peter Taylor‭

classification real-analysis inverse polynomials series

60%

+1 −0

Connection between caustics and conjugate points?

0 answers · posted 1y ago by tommi‭

differential-geometry

42%

+1 −2

What is the significance of the K-axiom in modal logic S5?

1 answer · posted 2mo ago by Julius H.‭ · edited 18d ago by xamidi‭

modal-logic proof-theory hilbert-systems axioms

Communities