In this paper we discuss the reason why the parameters of the Sérsic model best-fitting the major axis light profile of elliptical galaxies can differ significantly from those derived for the minor axis profile. We show that this discrepancy is a natural consequence of the fact that the isophote eccentricity varies with the radius of the isophote and present a mathematical transformation that a...

Recently, Mertens, Ono, and the third author studied mock modular analogues of Eisenstein series. Their coefficients are given by small divisor functions, have shadows classical Shimura theta functions. Here, we construct a class functions $\sigma^{\text{sm}}_{2,\chi}$ prove that these generate holomorphic part polar harmonic (weak) Maa{\ss} forms weight $\frac{3}{2}$. To this end, essentially ...

After the proof by R. Apéry of the irrationality of ζ(3) in 1976, a number of articles have been devoted to the study of Diophantine properties of values of the Riemann zeta function at positive integers. A survey has been written by S. Fischler for the Bourbaki Seminar in November 2002 [6]. Here, we review more recent results, including contributions by P. Bundschuh, S. Bruiltet, C. Elsner, S....