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2 votes
1 answer
321 views

A strange functional inequality

Let $f,g \in C([-2,2],\mathbb R_+^*)$ even and concave real functions. Is it true that $$ \int_0^1 f\big(\cos(x^{-1})+\sin(x^{-1})\big) \cdot g\big(\cos(x^{-1})-\sin(x^{-1})\big) \mathrm{d}x\\ \leq f(...
Dattier's user avatar
  • 4,074
2 votes
1 answer
125 views

For which value of $C(f)$ would the following inequality hold?

I am wondering what would be the value of $C(f)$ for the following inequality to hold? E.g., $C(f)$ could be some quantity related to the Lipschitz constant or the size of the domain. $$\left(\int f(x,...
Alec Wang's user avatar
2 votes
1 answer
137 views

Approximating a limit of an integral

How can we prove the following asymptotic lower bound for the regularized Beta function when $n\rightarrow\infty$? $$\int_0^{1} I_{2 t - t^2}\left(\frac{n - 1}{2}, \frac{1}{2}\right) dt=\Omega\left(\...
Penelope Benenati's user avatar
1 vote
1 answer
181 views

Optimization problem with definite integral inequality constraints

Question: How can we prove that there exists a real constant $c\ge 1$ such that the following inequality holds for all integers $d>1$ and all real numbers $r\in\left[1,\sqrt{d}\right]$? $$\int_{-1}^...
Penelope Benenati's user avatar
0 votes
1 answer
350 views

Uniformly Bounded (updating)

Suppose that $a_1<1$, $a_1+a_2+a_3>1.$ For $x,y,z>0,$ (1) define a fucntion $$H(x,y,z)=\frac{x^{\frac{1}{2}}\int_0^{\infty}\frac{1}{t^{a_1}~ (1+t)^{a_2+1}~ (1+t+z)^{a_3}}\exp\big\{-\frac{...
Xiaopai Song's user avatar
4 votes
0 answers
349 views

Fractional integral inequality (Hardy-Littlewood-Sobolev)

I am investigating the following integral \begin{equation} I^*(x) = \int_{\mathbb{R}} \frac{f(y) \ln |y-x| }{|y - x|^{\mu}} \, dy \end{equation} where $f \in L_p(\mathbb{R})$, $ 1 < p < q <...
Narek Margaryan's user avatar
3 votes
0 answers
103 views

Extension of the Gagliardo Inequality

The Gagliardo Inequality generalizes Fubini's Theorem: let $f_j$ be $d-1$ non-negative measurable functions over ${\mathbb R}^{d-1}$. Let us form the function $$f(x)=\prod_{j=1}^df_j(\widehat{x_j}),$$ ...
Denis Serre's user avatar
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