Exact String Solutions in 2+1-Dimensional De Sitter Spacetime

TL;DR

This paper derives exact string solutions in 2+1-dimensional de Sitter spacetime, revealing novel phenomena such as multiple string emergence from a single world-sheet and their dynamic behavior during cosmic expansion.

Contribution

It introduces explicit solutions linking string dynamics to the sinh-Gordon model in de Sitter space, highlighting new features absent in flat spacetime.

Findings

Multiple strings can emerge from a single world-sheet.

One string remains stable while another grows or shrinks with universe expansion.

String size and energy can grow or stabilize depending on the universe's radius.

Abstract

Exact and explicit string solutions in de Sitter spacetime are found. (Here, the string equations reduce to a sinh-Gordon model). A new feature without flat spacetime analogy appears: starting with a single world-sheet, several (here two) strings emerge. One string is stable and the other (unstable) grows as the universe grows. Their invariant size and energy either grow as the expansion factor or tend to constant. Moreover, strings can expand (contract) for large (small) universe radius with a different rate than the universe.