Relieving String Tension By Making Baby Universes in a Dynamical String Tension Braneworld Model

TL;DR

This paper proposes a mechanism for dynamically generating string tension using modified measures formalism, leading to a brane-world scenario where baby universes help mitigate back reactions from high tension strings.

Contribution

It introduces a novel dynamical string tension mechanism within a brane-world model, incorporating baby universe creation to address back reaction issues.

Findings

Strings can achieve near infinite tension confining them to close surfaces.

Baby universe creation helps neutralize back reactions from high tension.

The model avoids minimum length and maximum Hagedorn temperature constraints.

Abstract

String tension fundamentally determines the properties of strings; yet its value is often assigned arbitrarily, creating a fine-tuning problem. We describe a mechanism for dynamically generating string tension in a flat or almost flat spacetime, using the modified measures formalism, which in turn naturally generates a new type of stringy brane-world scenario. Such a scenario allows strings to achieve near infinite tension confining the strings to two very close expanding surfaces, but the infinite tensions also threatens to distort the near-flat embedding spacetime through large back reactions. We argue that this danger can be neutralised via the creation of a baby universe, a growing region of emdedding spacetime that divorces from the ambient embedding spacetime, while our universe is still a brane separating two nearly flat spacetimes. The avoidance of a minimum length and a maximum Hagedorn temperature in the context of dynamical string tension generation are also discussed.