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W2S
  • Member for 3 years, 10 months
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6 votes
1 answer
434 views

Basic questions about the sobolev space $H^\infty(\mathbb{R})$

5 votes
0 answers
178 views

Upgrading weak-convergence in $\mathbb{R}$ to strong-convergence in compact sets

4 votes
2 answers
237 views

Basic question about real-analytic functions

3 votes
1 answer
60 views

Continuity in $H^\theta$ implies weak convergence in $H^s$

3 votes
0 answers
25 views

Strong continuity of time-dependent functions with values in $H^s(\mathbb{R})$

3 votes
1 answer
43 views

Is there any function such that $f(x)\to0$ as $x\to \infty$ but $x\log(x) f'(x)\to +\infty$?

3 votes
1 answer
290 views

Change of variable vs Fundamental Theorem of Calculus

3 votes
2 answers
59 views

Schrodinger semigroup and conservation laws

2 votes
1 answer
62 views

Commutator operator into convolution operator

2 votes
0 answers
21 views

Estimate for the trace of some self adjoint non negative trace class operators

2 votes
2 answers
49 views

$f:[0,1)\to \mathbb{R}$ invertible and surjective (onto)?

2 votes
2 answers
81 views

Does there always exists coefficients $c,d\in\mathbb{R}$ s.t. $ax^3+bx^2+cx+d$ has three different real roots?

2 votes
0 answers
89 views

Application of Sobolev's embedding

1 vote
1 answer
88 views

Roots of the derivative of a nice polynomial function (with explicit roots)

1 vote
0 answers
60 views

One (a little bit more specific) question about real-analytic functions

1 vote
1 answer
65 views

Periodic solutions of $y'''+ay'+byy'=0$

1 vote
1 answer
52 views

Properties of the solutions for linear system with variable coefficients

1 vote
1 answer
46 views

Number of solutions of $x+\log\vert x\vert =a$ for $a\in\mathbb{R}$

1 vote
1 answer
99 views

Domain restrictions and interval of validity

1 vote
0 answers
35 views

Bounding $\Vert f''(x)\mathrm{sech}(x)\Vert_{L^2(\mathbb{R})}$ for functions $f$ supported on small frequencies.

1 vote
0 answers
32 views

Connecting eigenfunctions in different regions

0 votes
0 answers
17 views

Next term in the Stationary Phase Lemma expansion in dimension 2

0 votes
1 answer
26 views

Fourier Transform and conjugations

0 votes
2 answers
129 views

Antiderivative of a piecewise continuous function

0 votes
1 answer
44 views

Strong convergence for time-dependent functions

-1 votes
1 answer
45 views

Application of the mean value theorem $x\big(f(\tfrac{x}{n})-f(\tfrac{x-y}{n})\big)=O\Big(\vert y\vert f\big(\tfrac{x-y}{n}\big)\Big)$

-2 votes
1 answer
72 views

For $a>1$ and $x>y>0$, is it true that $(x-y)^a+y^a-x^a\leq 0$? [duplicate]