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2 votes
1 answer
160 views

Is the function $(z-1)(2^{z}-1)\zeta(z)$ logarithmically concave and convex in $z\in(0,\infty)$?

For proving that the sequence \begin{equation}\label{first-proof-decreas-seq} \frac{1}{(2k-1)(k+1)} \frac{2^{2k+2}-1}{2^{2k}-1} \biggl|\frac{B_{2k+2}}{B_{2k}}\biggr| \end{equation} is decreasing in $k\...
qifeng618's user avatar
  • 1,101
0 votes
0 answers
79 views

Is there an asymptotic expansion for the reciprocal of the classical Euler beta function?

The classical Euler beta function can be defined by $$ B(p,q)=\int_0^1t^{p-1}(1-t)^{q-1}\operatorname{d\!}t $$ for $\Re(p),\Re(q)>0$. The beta function and the classical Euler gamma function $\...
qifeng618's user avatar
  • 1,101
10 votes
7 answers
875 views

$\int_L^\infty \exp(- t - y/t) \, dt = \text{?}$

Let $y>0$, $L>0$. Has the (special?) function given by $$f(y,L) = \int_{L}^\infty e^{- t - y/t} \, dt$$ been studied? Are there precise, simple bounds? Let me try to attempt to reinvent the ...
H A Helfgott's user avatar
  • 20.2k
2 votes
1 answer
215 views

An integral transform computation

In Erdelyi, Tables of Integral Transforms, p. 344 Section 7.2. they note that \begin{align} \frac{1}{2 \pi i} \int_{c-i\infty}^{c+i\infty} s^{\nu} e^{\alpha s^2} x^{-s} \, ds = 2^{-\nu/2} \pi^{-...
user506603's user avatar
42 votes
7 answers
5k views

How should an analytic number theorist look at Bessel functions?

(And a related question: Where should an analytic number theorist learn about Bessel functions?) Bessel functions occur quite frequently in analytic number theory. One example, Corollary 4.7 of ...
Frank Thorne's user avatar
  • 7,347
2 votes
0 answers
376 views

Reflection formula for the Hurwitz zeta function and odd zeta values

A reflection formula for the Hurwitz zeta function, which does not seem to be well known, uses half of the polynomials generated by $\frac{1}{-1+\sqrt{t-1}\cot(\sqrt{t-1}u)}$. (Look at the sections "...
Wolfgang's user avatar
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5 votes
1 answer
1k views

Request for the proof of a result from Ramanujan's letter to Hardy.

Srinivasa Ramanujan in his first letter to G.H. Hardy stated many results for which he didn't give proofs. Among them the result taken from this link seems interesting : If $$\int\limits_{0}^{\infty} ...
C.S.'s user avatar
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