Mathematical Research Letters

Volume 7 (2000)

Number 1

Contents

A Sharp Estimate on the Norm of the Martingale Transform

Janine Wittwer

pp. 1-12

Perverse Sheaves on affine Grassmannians and Langlands Duality

Ivan Mirković and Kari Vilonen

pp. 13-24

Carathéodory-Fejér interpolation on polydisks

Jörg Eschmeier, Linda Patton, and Mihai Putinar

pp. 25-34

On the Unfolding of Folded Symplectic Structures

Victor Guillemin, Ana Cannas da Silva, and Christopher Woodward

pp. 35-53

Gerbes of chiral differential operators

Vassily Gorbounov, Fyodor Malikov, and Vadim Schechtman

pp. 55-66

Varieties without extra automorphisms~I: curves

Bjorn Poonen

pp. 67-76

Varieties without extra automorphisms II: hyperelliptic curves

Bjorn Poonen

pp. 77-82

A Maximal Operator and a Covering Lemma on Non-Compact Symmetric Spaces

Alexandru D. Ionescu

pp. 83-93

On level-lowering for mod 2 representations

Kevin Buzzard

pp. 96-110

Tautological formal Frobenius manifold structures on a Frobenius algebra

Jian Zhou

pp. 111-121

Hyperelliptic jacobians without complex multiplication

Yuri G. Zarhin

pp. 123-132

Harmonic Maps to Teichmüller Space

Georgios Daskalopoulos, Ludmil Katzarkov, and Richard Wentworth

pp. 133-146