Real elements in the mapping class group of T2T^2

We present a complete classification of elements in the mapping class group of the torus which have a representative that can be written as a product of two orientation reversing involutions. Our interest in such decompositions is motivated by features of the monodromy maps of real fibrations. We employ the property that the mapping class group of the torus is identifiable with $SL(2,\Z)$ as well as that the quotient group $PSL(2,\Z)$ is the symmetry group of the {\em Farey tessellation} of the Poincar\'e disk.Comment: 15 pages, 11 figure

Limit points of lines of minima in Thurston's boundary of Teichmueller space

Given two measured laminations mu and nu in a hyperbolic surface which fill up the surface, Kerckhoff [Lines of Minima in Teichmueller space, Duke Math J. 65 (1992) 187-213] defines an associated line of minima along which convex combinations of the length functions of mu and nu are minimised. This is a line in Teichmueller space which can be thought as analogous to the geodesic in hyperbolic space determined by two points at infinity. We show that when mu is uniquely ergodic, this line converges to the projective lamination [mu], but that when mu is rational, the line converges not to [mu], but rather to the barycentre of the support of mu. Similar results on the behaviour of Teichmueller geodesics have been proved by Masur [Two boundaries of Teichmueller space, Duke Math. J. 49 (1982) 183-190].Comment: Published by Algebraic and Geometric Topology at http://www.maths.warwick.ac.uk/agt/AGTVol3/agt-3-9.abs.htm