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3 votes
2 answers
585 views

How to integrate an exponential function of an exponential function?

Does any one know how to calculate the following integration? $$ \int_{\mathbb{R}} \left(\exp(z \: e^{-y^2})-1\right)^2 dy=?,\quad z>0. $$ This post is related to my previous question here , ...
Anand's user avatar
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2 votes
0 answers
379 views

Is this double integral of Fourier series always real?

Consider $f(x)$ a function from $\mathbb{R^+}$ to $\mathbb{C}$ such that $f(x) \sim_0 x$ and $\int_{0}^{\infty} f(x) dx=\int_{0}^{\infty} x^2 f(x) dx=0$ Can we demonstrate that following integral is ...
Bertrand's user avatar
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1 vote
0 answers
233 views

Fubini: can we interchange integration order on this double integral (with Fourier series product)

Can we interchange the order of integration of following double integral ? $$I = \int_{0}^{1} \int_{0}^{\infty} F(x,y) \overline{R(x,y)} - R(x,y) \overline{F(x,y)} \; dx \; dy$$ Where $F(x,y)= \...
Bertrand's user avatar
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