Finite momentum at string endpoints

TL;DR

This paper demonstrates that classical strings can have finite energy and momentum at their endpoints, which affects their propagation and energy loss in curved backgrounds like AdS5-Schwarzschild, with implications for heavy ion physics.

Contribution

It introduces the concept of finite endpoint momentum for classical strings and explores its effects on string dynamics and energy loss in curved spacetimes.

Findings

Strings with finite endpoint momentum can travel further in AdS5-Schwarzschild.

Endpoints must follow null geodesics if energy remains finite.

Proposes a scheme to determine energy loss rate.

Abstract

We argue that classical strings, both bosonic and supersymmetric, can have finite energy and momentum at their endpoints. We show that in a general curved background, string endpoints must propagate along null geodesics as long as their energy remains finite. Finite endpoint momentum allows strings with a fixed energy to travel a greater distance in an AdS5-Schwarzschild background than has been possible for classical solutions considered previously. We review the relevance to heavy ion phenomenology of the dependence of this distance on energy, and we propose a scheme for determining the instantaneous rate of energy loss.