Difference between revisions of "Ramanujan tau"

From specialfunctionswiki
Jump to: navigation, search
 
(One intermediate revision by the same user not shown)
Line 8: Line 8:
 
</gallery>
 
</gallery>
 
</div>
 
</div>
 
 
  
 
=Properties=
 
=Properties=
<div class="toccolours mw-collapsible mw-collapsed">
+
[[Ramanujan tau is multiplicative]]<br />
<strong>Theorem:</strong> $\tau(mn)=\tau(m)\tau(n)$ if [[Greatest common divisor|$\gcd$]]$(m,n)=1$
+
[[Ramanujan tau of a power of a prime]]<br />
<div class="mw-collapsible-content">
+
[[Ramanujan tau inequality]]<br />
<strong>Proof:</strong>
 
</div>
 
</div>
 
 
 
<div class="toccolours mw-collapsible mw-collapsed">
 
<strong>Theorem:</strong> $\tau(p^{r+1})=\tau(p)\tau(p^r)-p^{11}\tau(p^{r-1})$ whenever $p$ is prime and $r>0$
 
<div class="mw-collapsible-content">
 
<strong>Proof:</strong> █
 
</div>
 
</div>
 
  
<div class="toccolours mw-collapsible mw-collapsed">
+
=References=
<strong>Theorem:</strong> $|\tau(p)| \leq 2p^{\frac{11}{2}}$ for all primes $p$
 
<div class="mw-collapsible-content">
 
<strong>Proof:</strong> █
 
</div>
 
</div>
 
  
 
[[Category:SpecialFunction]]
 
[[Category:SpecialFunction]]

Latest revision as of 00:53, 23 December 2016

The Ramanujan tau function $\tau \colon \mathbb{N} \rightarrow \mathbb{Z}$ is defined by the formulas $$\displaystyle\sum_{n=1}^{\infty} \tau(n)q^n = q \prod_{n=1}^{\infty} (1-q^n)^{24} = \eta(z)^{24}=\Delta(z),$$ where $q=e^{2\pi i z}$ with $\mathrm{Re}(z)>0$, $\eta$ denotes the Dedekind eta function, and $\Delta$ denotes the discriminant modular form.

Properties

Ramanujan tau is multiplicative
Ramanujan tau of a power of a prime
Ramanujan tau inequality

References