Spinning gravitating Skyrmions in generalized Einstein-Skyrme model

TL;DR

This paper studies spinning gravitating Skyrmions with higher-derivative terms in a generalized Einstein-Skyrme model, revealing complex branch structures and the absence of isospinning solutions in a simplified submodel.

Contribution

It provides a detailed analysis of axially symmetric, self-gravitating spinning Skyrmions, including new solution branches and the behavior of solutions in different model sectors.

Findings

Multiple solution branches emerge at high angular frequencies.

'Cloudy' configurations act as bound states of Skyrmions and pion excitations.

No regular isospinning solutions exist in the self-dual submodel for non-zero angular frequency.

Abstract

We investigate properties of self-gravitating isorotating Skyrmions in the generalized Einstein-Skyrme model with higher-derivative terms in the matter field sector. These stationary solutions are axially symmetric, regular and asymptotically flat. We provide a detailed account of the branch structure of the spinning solutions in the topological sector of degree one. We show that additional branches of solutions appear, as the angular frequency increases above some critical value, these "cloudy" configurations can be considered as a bound system of the spinning Skyrmions and "pion" excitations in the topologically trivial sector. Considering the critical behavior of the isorotating solitons in the general Einstein-Skyrme model, we point out that there is no isospinning regular solutions in the reduced self-dual $\mathcal{L}_6+\mathcal{L}_0$ submodel for any non zero value of the angular frequency.