Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 32389

Questions about modular forms and related areas

5 votes

New series for $1/\pi$ based on Ramanujan's ideas

See page 5 in http://arxiv.org/abs/1112.3259 Are the series presented there somewhat related to your series (7)?
Zurab Silagadze's user avatar
16 votes
Accepted

A sum by Ramanujan for $\coth^{2}(5\pi)$

Using (see entry 24 on page 291 in Ramanujan's Notebooks II: http://www.plou) $$\frac{\pi e^{-2\pi z}}{2z[\cosh{(2\pi z)}-\cos{(2\pi z)}]}= \frac{1}{8\pi z^3}-\frac{1}{4z^2}+\frac{\pi}{4z}-\sum\limits …
Zurab Silagadze's user avatar
11 votes
1 answer
1k views

A curious property of Ramanujan's function $\tau(n)$

As it is well known, Ramanujan's $\tau(n)$ function can be defined through the power series expansion of the modular discriminant: $$\Delta(q)=q\prod\limits_{n=1}^\infty (1-q^n)^{24}=\sum \limits_{n …
Zurab Silagadze's user avatar
4 votes

Rogers-Ramanujan continued fraction $R(e^{-2 \pi \sqrt 5})$

The result $$\small R(e^{-2\pi\sqrt{5}})=\frac{\sqrt{5}}{1+\left[5^{3/4}\left(\frac{\sqrt{5}-1}{2}\right)^{5/2}-1\right]^{1/5}}-\frac{\sqrt{5}+1}{2}=\frac{\beta+2}{\beta+\sqrt[5]{\sqrt{1+\beta^{10}}-\ …
Zurab Silagadze's user avatar
10 votes
Accepted

Ramanujan's pi formulas with a twist

A general methods of construction of Ramanujan-type identities are outlined in http://arxiv.org/abs/1211.6563 (Some conjectured formulas for 1/Pi coming from polytopes, K3-surfaces and Moonshine, by G …
Zurab Silagadze's user avatar
9 votes

On Siegel mass formula

Try this reference https://arxiv.org/abs/1105.5759 (Notes on "Quadratic Forms and Automorphic Forms" from the 2009 Arizona Winter School, by J. Hanke). P.S. See also http://citeseerx.ist.psu.edu/view …
Zurab Silagadze's user avatar