Fascinating Dirichlet Beta Function Relationships
One important L-function - closely related to the Riemann zeta function - is known as Dirichlet’s beta function (also Catalan’s beta function) with its L-series (i.e. L1) sum over the integers and product over the primes expressions as follows 1/1 s – 1/3 s + 1/5 s – 1/7 s + 1/9 s – … = 1/(1 + 1/3 s ) * 1/(1 – 1/5 s ) * 1/(1 + 1/7 s ) * … Then in the simplest case when s = 1, we have, 1 – 1/3 + 1/5 – 1/7 + 1/9 – … = 3/4 * 5/4 * 7/8 * … = π/4. So the well-known Leibniz formula for π represents a special case of the Dirichlet beta function i.e. β(s), for s = 1. And when s = 1, 3, 5, … β(s), results in a value of the form kπ s , where k is a rational number. So for example β(3) = 1 – 1/3 3 + 1/5 3 – 1/7 3 + 1/9 3 – … = π 3 /32 and β(5) = 1 – 1/3 5 + 1/5 5 – 1/7 5 + 1/9 5 – … = 5π 5 /1536. Now this function can be connected with the Riemann zeta function in a surprising manner. For using a similar type ge