Search results for "MONODROMY"
showing 4 items of 44 documents
The monodromy groups of Dolgachev's CY moduli spaces are Zariski dense
2014
Let $\mathcal{M}_{n,2n+2}$ be the coarse moduli space of CY manifolds arising from a crepant resolution of double covers of $\mathbb{P}^n$ branched along $2n+2$ hyperplanes in general position. We show that the monodromy group of a good family for $\mathcal{M}_{n,2n+2}$ is Zariski dense in the corresponding symplectic or orthogonal group if $n\geq 3$. In particular, the period map does not give a uniformization of any partial compactification of the coarse moduli space as a Shimura variety whenever $n\geq 3$. This disproves a conjecture of Dolgachev. As a consequence, the fundamental group of the coarse moduli space of $m$ ordered points in $\mathbb{P}^n$ is shown to be large once it is not…
A note on coverings with special fibres and monodromy group $ S_{d}$
2012
We consider branched coverings of degree over with monodromy group , points of simple branching, special points and fixed branching data at the special points, where is a smooth connected complex projective curve of genus , and , are integers with . We prove that the corresponding Hurwitz spaces are irreducible if .
MR 3004007 Reviewed Chretien P. and Matignon M. Maximal wild monodromy in unequal characteristic. Journal of Number Theory (2013) 133, 1389--1408. Re…
2013
Let R be a complete discrete valuation ring of mixed characteristic (0, p) with fraction field K. The stable reduction theorem affirms that given a smooth, projective, geometrically connected curve over K, C/K, with genus \geq 2, there exists a unique finite Galois extension M/K minimal for the inclusion relation such that C_{M}:= C x M has stable reduction over M. A such extension is called monodromy extension of C/K and the Galois group Gal(M/K) is called the monodromy group of C/K. In this paper, the authors study stable models of p-cyclic covers of P^1_K. At first, they work with covers of arbitrarily high genus having potential good reduction. In particular, they determine for such cov…
Abelian Integrals: From the Tangential 16th Hilbert Problem to the Spherical Pendulum
2016
In this chapter we deal with abelian integrals. They play a key role in the infinitesimal version of the 16th Hilbert problem. Recall that 16th Hilbert problem and its ramifications is one of the principal research subject of Christiane Rousseau and of the first author. We recall briefly the definition and explain the role of abelian integrals in 16th Hilbert problem. We also give a simple well-known proof of a property of abelian integrals. The reason for presenting it here is that it serves as a model for more complicated and more original treatment of abelian integrals in the study of Hamiltonian monodromy of fully integrable systems, which is the main subject of this chapter. We treat i…