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 69, Number 3

#### Publication Date: March 1993

Some geometric aspects of graphs and their eigenfunctions

Joel Friedman; 487-525

Two two-dimensional terminations

Valery Alexeev; 527-545

Characters, dual pairs, and unitary representations

Tomasz Przebinda; 547-592

Jorgensen’s inequality for discrete groups in normed algebras

Shmuel Friedland and Sa’ar Hersonsky; 593-614

Constructing free actions on $\mathbf{R}$-trees

Gilbert Levitt; 615-633

Local existence and stability of multivalued solutions to determined analytic first-order systems on the plane

Marek Kossowski; 635-661

Ample and spanned vector bundles with large $c^2_1$ relative to $c_2$ on surfaces

Atsushi Noma; 663-669

On the radial variation of bounded analytic functions on the disc

J. Bourgain; 671-682

Periodic solutions to some $N$-body type problems: the fixed energy case

Pietro Majer and Susanna Terracini; 683-697