ﻻ يوجد ملخص باللغة العربية
We prove that the triviality of the Galois action on the suitably twisted odd-dimensional etale cohomogy group of a smooth projective varietiy with finite coefficients implies the existence of certain primitive roots of unity in the field of definition of the variety. This text was inspired by an exercise in Serres Lectures on the Mordell--Weil theorem.
We prove various finiteness and representability results for flat cohomology of finite flat abelian group schemes. In particular, we show that if $f:Xrightarrow mathrm{Spec} (k)$ is a projective scheme over a field $k$ and $G$ is a finite flat abelia
The classification of lepton mixing matrices from finite residual symmetries is reviewed, with emphasis on the role of vanishing sums of roots of unity for the solution of this problem.
We give an explicit conjectural formula for the motivic Euler characteristic of an arbitrary symplectic local system on the moduli space A_3 of principally polarized abelian threefolds. The main term of the formula is a conjectural motive of Siegel m
At roots of unity the $N$-state integrable chiral Potts model and the six-vertex model descend from each other with the $tau_2$ model as the intermediate. We shall discuss how different gauge choices in the six-vertex model lead to two different quan
The goal of this paper is to calculate the trace of the composition of a Hecke correspondence and a (high enough) power of the Frobenius at a good place on the intersection cohomology of the Satake-Baily-Borel compactification of certain Shimura vari