Tony's user avatar
Tony's user avatar
Tony's user avatar
Tony
  • Member for 9 years, 7 months
  • Last seen more than 2 years ago
19 votes
3 answers
10k views

Meaning of the inverse of the Laplacian matrix

12 votes
1 answer
2k views

Can we construct a function that has uncountable many jump discontinuities?

9 votes
2 answers
3k views

Help provide a proof of the Helly–Bray theorem

9 votes
3 answers
2k views

Proof of the inequality $e^x\le e^{x^2} + x$ [duplicate]

8 votes
1 answer
623 views

Show $\lim_{m \to \infty ,n \to \infty } f(\frac{{\left\lfloor {mx} \right\rfloor }}{m},\frac{{\left\lfloor {ny} \right\rfloor }}{n}) = f(x,y)$

8 votes
3 answers
634 views

A question about the definition of generalized eigenspace

8 votes
1 answer
1k views

Any method to efficiently compute SVD of a perturbation of matrix $\bf A$ if the SVD of $\bf A$ is already known?

8 votes
2 answers
5k views

How the Bayes rule for density functions is formulated in probability theory?

7 votes
0 answers
211 views

Find the analytical form or the order of the spectral radius (or eigenvalues) of a special sparse matrix.

7 votes
2 answers
208 views

Show that $\lim_{\epsilon\to0^{+}}\frac{1}{2\pi i}\int_{\gamma_\epsilon}\frac{f(z)}{z-a} \, dz=f(a)$

7 votes
4 answers
237 views

Prove that if A is a non-(Lebesgue)measurable set and $d(A,B)>0$, show that $A⋃B$ is non-measurable

7 votes
2 answers
2k views

Is every $\sigma$-algebra generated by a partition?

7 votes
1 answer
3k views

Maximum principle for harmonic functions on unbounded domain

6 votes
1 answer
520 views

An interesting semi-linear PDE problem

6 votes
2 answers
4k views

Is outer measure a measure?

6 votes
3 answers
1k views

Show $\Bbb R ^n$ with a finite set removed is still connected.

6 votes
2 answers
1k views

How does the Vitali set violate the definition of measurable sets?

6 votes
0 answers
1k views

If $f$ and $g$ are measurable and well-defined a.e., show $f+g$ is measurable. [duplicate]

6 votes
2 answers
171 views

Help explain why "$f$ be finite a.e" is necessary in a theorem.

6 votes
1 answer
653 views

How to calculate the area of a hyperplane

6 votes
2 answers
886 views

Help with a minimum-distance permutation problem

6 votes
1 answer
442 views

Is $f(C)$ a convex set if $f$ and $C$ are convex?

6 votes
1 answer
290 views

How to show the optimization/ODE fixed point iteration steps converge?

6 votes
1 answer
149 views

A sequence ${\bf x}_1,{\bf x}_2,{\bf x}_3,...$ converges geometrically in some norm, will it converge geometrically in any equivalent norm?

6 votes
1 answer
1k views

Given a $3 \times 3$ matrix, left multiply or right multiply unitary matrices (e.g. householder reflector) to introduce zeros.

5 votes
1 answer
825 views

Is Hermitian matrix a self-adjoint operator w.r.t. just the standard inner product, or any inner product?

5 votes
2 answers
274 views

Help understand equivalence of two optimization problems

5 votes
0 answers
2k views

Any known relationship between the eigenvalues of correlation matrix and covariance matrix?

5 votes
1 answer
184 views

$f$ entire but not polynomial then $\lim_{n\to\infty}\sup \{|z|:p_n(z)=0\}\to\infty$, where $p_n$ is $n-th$ Taylor series of $f$

5 votes
2 answers
2k views

Why it is more accurate to evaluate $x^2-y^2$ as $(x+y)(x-y)$ in floating point system?

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