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Related papers: A Ramanujan enigma: Part 2

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In this paper, we evaluate in closed form several different series involving the harmonic numbers and skew-harmonic numbers. We consider two classes of series involving these sequences. One class of series involves the product of the $n$th…

Classical Analysis and ODEs · Mathematics 2025-10-20 Vincent Nguyen

An asymptotic series in Ramanujan's second notebook (Entry 10, Chapter 3) is concerned with the behavior of the expected value of $\phi(X)$ for large $\lambda$ where $X$ is a Poisson random variable with mean $\lambda$ and $\phi$ is a…

Statistics Theory · Mathematics 2009-10-25 Yaming Yu

Ramanujan, in his famous first letter to Hardy, claimed a very precise estimate for the number of integers that can be written as a sum of two squares. Far less well-known is that he also made further claims of a similar nature for the…

Number Theory · Mathematics 2025-09-08 Bruce C. Berndt , Pieter Moree

An identity by Ramanujan related to the multisection of Bernoulli numbers is revisited. Two alternative approaches are proposed, both relying on the multisection technique. A geometric approach reveals the role played by the symmetries of…

Number Theory · Mathematics 2025-09-03 Parth Chavan , Christophe Vignat

On page 206 in his lost notebook, Ramanujan recorded a seventh degree identity for his theta function $\varphi(q)$. We give an analogous ninth degree identity. We also provide an application of an entry from his second notebook on a cubic…

Number Theory · Mathematics 2025-06-03 Sun Kim , Örs Rebák

In the spirit of Ramanujan, we derive exponentially fast convergent series for Epstein zeta functions $ E^{\varGamma_0(N)}(z,s)$ on the Hecke congruence groups $ \varGamma_0(N),N\in\mathbb Z_{>0}$, where $z$ is an arbitrary point in the…

Classical Analysis and ODEs · Mathematics 2016-04-29 Yajun Zhou

In this paper, the authors present sharp approximations in terms of sine function and polynomials for the so-called Ramanujan constant (or the Ramanujan $R$-function) $R(a)$, by showing some monotonicity, concavity and convexity properties…

Complex Variables · Mathematics 2018-04-23 Song-Liang Qiu , Xiao-Yan Ma , Ti-Ren Huang

Using a pair of two variable series-product identities recorded by Ramanujan in the lost notebook as inspiration, we find some new identities of similar type. Each identity immediately implies an infinite family of Rogers-Ramanujan type…

Number Theory · Mathematics 2019-01-17 James Mc Laughlin , Andrew V. Sills

Very recently, Radchenko and Zagier revived the theory of Herglotz functions. The main goal of the article is to show that one of the formulas on page 220 of Ramanujan's Lost Notebook actually lives in the realms of this theory. As a…

Number Theory · Mathematics 2022-04-12 Rajat Gupta , Rahul Kumar

We revisit several entries from Ramanujan's notebooks which follow from more elementary arguments than a first glance may suggest. Our goal is to demystify these results through more accessible proofs, while also shining some light on the…

History and Overview · Mathematics 2026-05-12 Zachary P. Bradshaw , C. Vignat

We prove some "divergent" Ramanujan-type series for $1/\pi$ and $1/\pi^2$ applying a Barnes-integrals strategy of the WZ-method.

Number Theory · Mathematics 2012-10-16 Jesus Guillera

In the present paper, we introduce a multiple Ramanujan sum for arithmetic functions, which gives a multivariable extension of the generalized Ramanujan sum studied by D. R. Anderson and T. M. Apostol. We then find fundamental arithmetic…

Number Theory · Mathematics 2012-12-07 Yoshinori Yamasaki

Inspired by a famous formula of Ramanujan for odd zeta values, we prove an analogous formula involving the Hurwitz zeta function. We introduce a new integral kernel related to the Hurwitz zeta function, generalizing the integral kernel…

Number Theory · Mathematics 2022-05-18 Parth Chavan

We define bilateral series related to Ramanujan-like series for $1/\pi^2$. Then, we conjecture a property of them and give some applications.

Number Theory · Mathematics 2019-06-05 Jesús Guillera

During the course of verifying the results of Ramanujan on hypergeometric series, Berndt in his notebooks, Part II mentioned corrected forms of two of the Ramanujan's results. The aim of this short research note is to point out that one of…

Complex Variables · Mathematics 2013-02-21 Medhat A. Rakha , Adel K. Ibrahim , Arjun K. Rathie

Ramanujan's Master Theorem is a decades-old theorem in the theory of Mellin transforms which has wide applications in both mathematics and high energy physics. The unconventional method of Ramanujan in his proof of the theorem left…

Classical Analysis and ODEs · Mathematics 2025-01-08 Zachary P. Bradshaw , Omprakash Atale

In his third notebook, Ramanujan claims that $$ \int_0^\infty \frac{\cos(nx)}{x^2+1} \log x \,\mathrm{d} x + \frac{\pi}{2} \int_0^\infty \frac{\sin(nx)}{x^2+1} \mathrm{d} x = 0. $$ In a following cryptic line, which only became visible in a…

Classical Analysis and ODEs · Mathematics 2015-10-15 Bruce C. Berndt , Armin Straub

This book deals with functions allowing to express the dissimilarity (discrepancy) between two data fields or ''divergence functions'' with the aim of applications to linear inverse problems. Most of the divergences found in the litterature…

Optimization and Control · Mathematics 2020-03-04 Henri Lantéri

Infinite series are evaluated through the manipulation of a series for $\cos(2t \sin^{-1}x)$ resulting from Clausen's Product. Hypergeometric series equal to an expression involving $\frac{1} {\pi}$ are determined. Techniques to evaluate…

Number Theory · Mathematics 2015-03-17 John M. Campbell

A simple integration by parts and telescopic cancellation leads to a rigorous derivation of the first 2 terms for the error in Ramanujan's asymptotic series for the nth partial sum of the harmonic series. Then Kummer's transformation gives…

Classical Analysis and ODEs · Mathematics 2007-05-23 Mark B. Villarino