# Anomalous quartic term in the expansion of the symmetry energy

## TL;DR

This paper investigates the quartic term in the symmetry energy within relativistic mean field theory, revealing it can become very large and questioning the validity of the standard even power expansion due to potential non-analytic contributions.

## Contribution

It introduces the possibility of significant non-analytic contributions to the symmetry energy, challenging the conventional polynomial expansion approach.

## Key findings

- Quartic term can reach very large values in the model.
- Standard even power expansion may be inadequate.
- Non-analytic contributions might be important.

## Abstract

The quartic term in the framework of relativistic mean field theory with inclusion of scalar meson interactions is investigated. It is shown that the quartic term in the asymmetric expansion of nuclear matter energy may reach very large values. This makes the even power expansion of asymmetry questionable and suggests possible non-analytic contributions to the energy of matter.