18-23 March 2018
Florianopolis, Brazil
America/Sao_Paulo timezone

## Isospin matter and pion stars

20 Mar 2018, 16:00
1h
Florianopolis, Brazil

Poster

### Speaker

Mauricio Hippert Teixeira (Universidade Federal do Rio de Janeiro)

### Description

We explore the condensation of charged pions in the presence of a large isospin chemical potential, in the absence of baryons, within the Linear Sigma Model. A mean-field expansion is used to calculate the thermodynamics and the spectrum of excitations of the pion-condensed medium. The pion condensate is shown to explicitly break the $U(1)_{\tau_3}$ vector isospin symmetry associated with electromagnetic gauge invariance, making it a superconductor.

Results are successfully compared to lattice calculations and used to find the equation of state of isospin matter, made electrically neutral by the addition of leptons. From the obtained equation of state, we calculate the mass-radius relation of a new class of compact stars: pion stars, which are found to have masses of up to $\sim 230\, M_\odot$, with radii of $\sim 10^2 - 10^5$ km.

### Summary

We study the condensation of pions under a large isospin chemical potential, in the absence of baryons. As an application, we calculate the mass-radius relation of pion stars, a new class of compact stars.

### Primary authors

Bastian Brandt (Frankfurt University) Eduardo Fraga (Universidade Federal do Rio de Janeiro) Gergely Endrodi (Frankfurt University) Juergen Schaffner-Bielich (Frankfurt University) Mauricio Hippert Teixeira (Universidade Federal do Rio de Janeiro) Sebastian Schmalzbauer (Frankfurt University)

### Presentation materials

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