Now showing items 31-40 of 43
Abelian quotients of subgroups of the mapping class group and higher Prym representations
(London Mathematical Society, 2013-08)
A well-known conjecture asserts that the mapping class group of a surface (possibly with punctures/boundary) does not virtually surject onto Z if the genus of the surface is large. We prove that if this conjecture holds ...
Small generating sets for the Torelli group
(Mathematical Sciences Publisher, 2012)
Proving a conjecture of Dennis Johnson, we show that the Torelli subgroup Ig of the genus g mapping class group has a finite generating set whose size grows cubically with respect to g. Our main tool is a new space called ...
Ergodic properties of compositions of interval exchange maps and rotations
(IOP Publishing, 2012)
We study the ergodic properties of compositions of interval exchange transformations (IETs) and rotations. We show that for any IET T, there is a full measure set of α ∈ [0, 1) so that T Rα is uniquely ergodic, where Rα is ...
The Weil-Peterson Hessian of Length on Teichmuller Space
(International Press, 2012)
We present a brief but nearly self-contained proof of a formula for the Weil-Petersson Hessian of the geodesic length of a closed curve (either simple or not simple) on a hyperbolic surface. The formula is the sum of the ...
Failure of the Hasse Principle on General K3 Surfaces
(Oxford University Press, 2013)
We show that transcendental elements of the Brauer group of an algebraic surface can obstruct the Hasse principle. We construct a general K3 surface X of degree 2 over Q, together with a two-torsion Brauer class that is ...
The Rational Cohomology of the Mapping Class Group Vanishes in its Virtual Cohomological Dimension
(Oxford University Press, 2012)
Filtering smooth concordance classes of topologically slice knots
We propose and analyze a structure with which to organize the difference between a knot in S3 bounding a topologically embedded 2–disk in B4 and it bounding a smoothly embedded disk. The n–solvable filtration of the ...
Cocycle rigidity and splitting for some discrete parabolic actions
(American Institute of Mathematical Sciences, 2014)
Anderson localization for quasi-periodic CMV matrices and quantum walks
We consider CMV matrices, both standard and extended, with analytic quasi-periodic Verblunsky coefficients and prove Anderson localization in the regime of positive Lyapunov exponents. This establishes the CMV analog of a ...