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3 votes
0 answers
143 views

Extrapolated Integral operator (compactness)

I am studying the compactness of some convolution operators. Let the convolution with extrapolation $$ \Gamma: X\longrightarrow X; x\mapsto\int_0^t T_{-1}(t-s)B(s)x\mathrm{d}s. $$ Here $T(\cdot)$ is a ...
Malik Amine's user avatar
4 votes
1 answer
237 views

Integral operator (compactness)

I am studying the compactness of some convolution operators. Let the convolution $$ \Gamma: X\longrightarrow X; x\mapsto\int_0^t T(t-s)B(s)x\mathrm{d}s. $$ Here $T(\cdot)$ is a $C_0$-semigroup on some ...
Malik Amine's user avatar
4 votes
1 answer
2k views

Norm of convolution operator

By Young's inequality for any $f\in L^p(\mathbf{R})$ the map $T_f:g\mapsto f\star g$ is a continuous operator from $L^q(\mathbf{R})$ to $L^r(\mathbf{R})$ where $1\leq p,q,r\leq \infty$ satisfy $1+\...
Ayman Moussa's user avatar
  • 3,000
1 vote
1 answer
372 views

Is this operator invertible?

Let $T(t)$ be a strongly continuous semi-group on a Banach space $X$, and let $A(\cdot)\in C(0,\tau; \mathcal{L}(X))$ for some $\tau>0$. The operator $G:C(0,\tau;X)\to C(0,\tau;X)$ maps every $h\in ...
Saj_Eda's user avatar
  • 395
3 votes
0 answers
118 views

Any chance to get the moments of this exotic distribution?

Let us define the following cumulative distribution: \begin{align} \Pr (Y(t)\geq a)=\sum_{n=0}^\infty \frac{e^{-kt}(kt)^n }{n!}\int_a^\infty[\circledast_{f}\circ H_a ]^n\delta (x) dx \end{align} where ...
Alexandre's user avatar
  • 368
3 votes
1 answer
458 views

Norm inequality for convolution operators on groups

Let $G$ be a discrete, finitely generated group. Let $f\in \mathbb{C} G$ be given. Consider $g\in G\setminus \operatorname{supp} f$ and let $\delta_g$ denote the Dirac delta at $g$. Is it true ...
user10439561's user avatar