Contents Online

# Mathematical Research Letters

## Volume 27 (2020)

### Number 4

### Contents

Applications of nonarchimedean developments to archimedean nonvanishing results for twisted $L$‑functions

pp. 973-1002

Upper semi-continuity of entropy in non-compact settings

pp. 1055-1077

Mapping class group is generated by three involutions

pp. 1095-1108

On $L^1$ endpoint Kato–Ponce inequality

pp. 1129-1163

Chekanov’s dichotomy in contact topology

pp. 1165-1193

Sphere theorems for submanifolds in Kähler manifold

pp. 1195-1236

Rational curves on elliptic K3 surfaces

pp. 1237-1247