D'Lima, M.;
(2011)
Prol fundamental groups of generically ordinary semistable fibrations with low slope.
Doctoral thesis , UCL (University College London).

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Abstract
Let k be an algebraically closed field of characteristic p > 0 and l a prime that is distinct from p. Let f : S \rightarrow C be a generically ordinary, semistable fibration of a projective smooth surface S to a projective smooth curve C over k. Let F be a general fibre of f, which is a smooth curve of genus g \geq 2. We assume that f is generically strongly lordinary, by which we mean that every cyclic etale covering of degree l of the generic fibre of f is ordinary. Suppose that f is not locally trivial and is relatively minimal. Then deg f*\omegaS/C > 0, where \omegaS/C is the sheaf associated to the relative canonical divisor KS/C = KS − f*KC. Hence the slope of f,\lambda( f ) = K2 S/C/deg f*\omegaS/C is welldefined. Consider the pushout square \pi1(F) \rightarrow \pi1(S) \rightarrow \Pi(C) \rightarrow 1 \downarrow \Pi where \pi1 is the algebraic fundamental group and \pil1 is the prol fundamental group. When f is nonhyperelliptic and \lambda(f) < 4, we show that the morphism \pil1(F)\rightarrow /alpha\Pi is trivial.
Type:  Thesis (Doctoral) 

Title:  Prol fundamental groups of generically ordinary semistable fibrations with low slope 
Open access status:  An open access version is available from UCL Discovery 
Language:  English 
Additional information:  The abstract contains LaTeX text. Please see the attached pdf for rendered equations 
UCL classification:  UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Mathematics 
URI:  http://discovery.ucl.ac.uk/id/eprint/1318074 
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