文摘
The period polynomial of a cusp form of an integral weight plays an important role in the number theory. In this paper, we study the period function of a cusp form of real weight. We obtain a series expansion of the period function of a cusp form of real weight for class="mathmlsrc">class="formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0022314X16302037&_mathId=si1.gif&_user=111111111&_pii=S0022314X16302037&_rdoc=1&_issn=0022314X&md5=f9d0ebaf41ba69d09651b434fad6e739" title="Click to view the MathML source">SL(2,Z)class="mathContainer hidden">class="mathCode"> by using the binomial expansion. Furthermore, we study two kinds of Hecke operators acting on cusp forms and period functions, respectively. With these Hecke operators we show that there is a Hecke-equivariant isomorphism between the space of cusp forms and the space of period functions. As an application, we obtain a formula for a certain L-value of a Hecke eigenform by using the series expansion of its period function.