Difference between revisions of "Dirichlet beta"

From specialfunctionswiki
Jump to: navigation, search
Line 2: Line 2:
 
$$\beta(x) = \displaystyle\sum_{k=0}^{\infty} (-1)^k (2k+1)^{-x} = 2^{-x} \Phi \left(-1,x,\dfrac{1}{2} \right),$$
 
$$\beta(x) = \displaystyle\sum_{k=0}^{\infty} (-1)^k (2k+1)^{-x} = 2^{-x} \Phi \left(-1,x,\dfrac{1}{2} \right),$$
 
where $\Phi$ denotes the [[Lerch transcendent]].
 
where $\Phi$ denotes the [[Lerch transcendent]].
 +
 +
 +
<div align="center">
 +
<gallery>
 +
File:Plot dirichlet beta.png|Graph of $\beta$ on $[-4,4]$.
 +
File:Domain coloring dirichlet beta.png|[[Domain coloring]] of [[analytic continuation]] of $\beta$.
 +
</gallery>
 +
</div>
  
 
=Properties=
 
=Properties=
 
{{:Catalan's constant using Dirichlet beta}}
 
{{:Catalan's constant using Dirichlet beta}}

Revision as of 18:58, 25 July 2015

The Dirichlet $\beta$ function is defined by $$\beta(x) = \displaystyle\sum_{k=0}^{\infty} (-1)^k (2k+1)^{-x} = 2^{-x} \Phi \left(-1,x,\dfrac{1}{2} \right),$$ where $\Phi$ denotes the Lerch transcendent.


Properties

Theorem

The following formula holds: $$K=\beta(2),$$ where $K$ is Catalan's constant and $\beta$ denotes the Dirichlet beta function.

Proof

References