# Dynamics of junctions and the multi-tension velocity-dependent one-scale model

## TL;DR

This paper investigates the dynamics of string junctions in cosmic superstring networks, enhancing the velocity-dependent one-scale model to better understand their evolution and the impact of junctions on network behavior.

## Contribution

It introduces an improved semi-analytic model incorporating junction dynamics and small-scale structure effects into the velocity-dependent one-scale framework.

## Key findings

- Derived kinematic constraints for string collisions.
- Quantified the growth/reduction rates of string junctions.
- Enhanced the modeling accuracy of cosmic superstring network evolution.

## Abstract

The dynamics of string junctions and their influence on the evolution of cosmic superstring networks are studied in full detail. We review kinematic constraints for colliding strings in a Friedmann-Lema\^itre-Robertson-Walker background and obtain the average distribution of possible string configurations after string collisions. The study of small-scale structure enables us to investigate the average growth/reduction rate of string junctions for a given cosmic string network. Incorporating the averaged junction dynamics into the velocity-dependent one-scale model for multi-tension string networks, we improve the semi-analytic description and quantitative understanding of cosmic superstring network evolution.