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3 votes
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Volume of 3-dimensional region

$\newcommand\si\sigma$The expression $\Gamma(\Pi)$ makes no sense, and hence the definition of $F$ in your post makes no sense. Replacing $\Gamma$ by $\phi$, we get a definition which does makes sense:...
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6 votes

Integration in the surreal numbers

In a recent article in the Notices of the AMS, Philip Ehrlich briefly describes some progress in this area. Below is a relevant excerpt from the article. Conway originally expressed doubt that “...
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1 vote

Is there a formula or algorithm to remove infinitesimal and oscillating parts from an expression while keeping finite and infinite ones?

This isn't an answer, just a long comment. If this is from an established field, and I'd guess it is, that needs to be part of the question. Not knowing one, I will blindly sally forth because I am ...
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0 votes

Class of Riemann integrable functions with antiderivative

Just a modest proposal so a comment (but I am not entitled). Every Riemann (even Lebesgue) integrable function, say on the line, can be regarded in a natural way as a distribution (the distributional ...
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3 votes

Class of Riemann integrable functions with antiderivative

A classical and simple example is given by the function $x \mapsto \sin\frac{1}{x}$ extended by $0\mapsto 0$, on (say) $[-1,1]$: It is discontinuous at $0$. It is a derivative (= has an ...
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4 votes
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Definite integral of Bessel function of the first kind times $x^{3/2}$

The integral requires $\nu>-5/2$ for convergence, and then becomes a hypergeometric function: $$\int_0^a x^{3/2} J_\nu (bx) dx=\frac{2^{1-\nu} a^{\nu+\frac{5}{2}} b^{\nu}}{(2 \nu+5) \Gamma (\nu+1)}\...
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4 votes

References for $\int_{-\infty}^\infty\binom{1}{t}^3\,\mathrm dt=\frac{3}{2}+\frac{6}{\pi^2}$ and related integrals?

comment $$ \binom{t}{1} = \frac{1}{\Gamma(t+1)\Gamma(2-t)} = \frac{\sin((t+1)\pi)}{t(t-1)\pi} $$ Using this, Maple does the indefinite integrals in terms of the functions ${\rm Si}$ and ${\rm Ci}$. ...
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0 votes
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Could variable be still function in x and y after performing Reynolds averaging over area

Based on the comment by @CarloBeenakker, Coarse-grain averaging could be performed on a subset of the domain (spatial or temporal) so that the averaged value still varies with the independent ...
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