The 2-adic valuations of the algebraic central $L$-values for quadratic twists of weight 2 newforms

Abstract

Let $f$ be a normalized newform of weight 2 on ${\Gamma }_0(N)$ whose coefficients lie in $\mathbb{Q}$ and let ${\chi }_M$ be a primitive quadratic Dirichlet character with conductor $M$. In this paper, under mild assumptions on $M$, we give a sharp lower bound of the 2-adic valuation of the algebraic central $L$-value $L(f,{\chi }_M,1)$ and evaluate the 2-adic valuation for an infinite number of $M$.

To appear in Acta Arithmetica