Published by Duke University Press since its inception in 1935, the Duke Mathematical Journal is one of the world's leading mathematical journals. Without specializing in a small number of subject areas, it emphasizes the most active and influential areas of current mathematics.

### Volume 97, Number 1

#### Publication Date: 15 March 1999

An exact mass formula for orthogonal groups

Goro Shimura; 1-66

Maximal operators over arbitrary sets of directions

Nets Hawk Katz; 67-79

Variation de la hauteur de faltings dans une classe de $\overline\mathbb{Q}$-isogénie de courbe elliptique

Lucien Szpiro and Emmanuel Ullmo; 81-97

Counting rational curves on ${\text{K3}}$ surfaces

Arnaud Beauville; 99-108

Characteristic cycles for the loop Grassmannian and nilpotent orbits

Sam Evens and Ivan Mirković; 109-126

Limit theorems for theta sums

Jens Marklof; 127-153

Rigid cohomology and invariant cycles for a semistable log scheme

Bruno Chiarellotto; 155-169

The Frobenius and monodromy operators for curves and abelian varieties

Robert Coleman and Adrian Iovita; 171-215

Correction to “Modular invariant theory of parabolic subgroups of $GL_n (\mathbb{F}_q )$ and the associated Steenrod modules”

Thomas Hewett; 217