# Projective varieties with bad semi-stable reduction at 3 only

### Victor Abrashkin

Department of Mathematical Sciences Durham University Science Laboratories, South Rd, Durham DH1 3LE United Kingdom

## Abstract

Suppose $F=W(k)[1/p]$ where $W(k)$ is the ring of Witt vectors with coefficients in algebraically closed field $k$ of characteristic $p\ne 2$. We construct integral theory of $p$-adic semi-stable representations of the absolute Galois group of $F$ with Hodge-Tate weights from $[0,p)$. This modification of Breuil's theory results in the following application in the spirit of the Shafarevich Conjecture. If $Y$ is a projective algebraic variety over $\Q$ with good reduction modulo all primes $l\ne 3$ and semi-stable reduction modulo 3 then for the Hodge numbers of $Y_C=Y\otimes _{\Q}\ C$, one has $h^2(Y_C)=h^{1,1}(Y_C)$.

## Cite this article

Victor Abrashkin, Projective varieties with bad semi-stable reduction at 3 only. Doc. Math. 18 (2013), pp. 547–619

DOI 10.4171/DM/409