The Hodge Laplacian operator on 1-forms on $\mathbb{H}$ and 1-form $E_\mathfrak{a}^1$

Abstract

As is well known, we can average the eigenfunction $y^s$ of the hyperbolic Laplacian on the hyperbolic plane by $\Gamma$ a lattice in $\mathbf{SL}(2,\mathbb{R})$ to obtain an automorphic form: the non-holomorphic Eisenstein series $E_\mathfrak{a}(z,s)$. In this note, we choose a particular eigenfunction $y^s dx$ of the Hodge-Laplace operator for 1-forms on the hyperbolic plane $\mathbb{H}$. We can average $y^s dx$ by $\Gamma$ to define a 1-form $E_\mathfrak{a}^1 \big( (z,v), s \big)$. We shall prove that $E_\mathfrak{a}^1$ admits a Fourier expansion and calculates the corresponding coefficients. Also, we evaluate the integral $\int_{\gamma} E_\mathfrak{a}^1$ for when $\gamma$ is a lifting of horocycles and closed geodesics in the unit tangent bundle. Finally, we will obtain an analog to the Rankin-Selberg method for $E_\mathfrak{a}^1$ via horocycles.