# A generalisation of Kani-Rosen decomposition theorem for Jacobian varieties

## TL;DR

This paper extends the Kani-Rosen decomposition theorem, enabling broader isogeny decompositions of Jacobian varieties of Riemann surfaces with group actions, where all factors are Jacobians.

## Contribution

It generalizes the Kani-Rosen theorem to include more Jacobian varieties, expanding the scope of isogeny decompositions with Jacobian factors.

## Key findings

- Extended the class of Jacobians decomposable via isogenies
- Provided a new framework for Jacobian decomposition with group actions
- Broadened understanding of Jacobian structures in algebraic geometry

## Abstract

In this short paper we generalise a theorem due to Kani and Rosen on decomposition of Jacobian varieties of Riemann surfaces with group action. This generalisation extends the set of Jacobians for which it is possible to obtain an isogeny decomposition where all the factors are Jacobians.