# A new type of dark compact objects in massive tensor-multi-scalar theories of gravity

## TL;DR

This paper introduces a new class of compact objects called tensor-multi-scalar solitons in certain gravity theories, which could have significant implications for understanding dark matter.

## Contribution

It demonstrates the existence of tensor-multi-scalar solitons in specific tensor-multi-scalar gravity theories through solving a non-linear eigenvalue problem, highlighting their potential role in dark matter.

## Key findings

- Tensor-multi-scalar solitons can have masses from neutron stars to galactic centers.
- Existence of these solitons is proven mathematically within the theories.
- They may constitute part of dark matter.

## Abstract

In the present paper we consider special classes of tensor-multi-scalar theories of gravity whose target-space metric admits Killing field(s) with a periodic flow. For such tensor-multi-scalar theories we show that if the dynamics of the scalar fields is confined on the periodic orbits of the Killing field(s) then there exists a new type of compact objects - the tensor-multi-scalar solitons formed by a condensation of the gravitational scalars. The existence of the tensor-multi-scalar solitons is proven by solving the fully non-linear eigenvalue problem which follows from the dimensional reduction of the field equations of tensor-multi-scalar theories of gravity. The mass of the tensor-multi-scalar solitons can range at least from the mass of a neutron star to the mass of dark objects in the center of the galaxies in dependence of mass(es) of the gravitational scalars and which sector of massive scalars is excited. These facts show that the tensor-multi-scalar solitons could have important implications for the dark matter problem. The existence of the tensor-multi-scalar solitons points towards the possibility that the dark matter, or part of it, is made of condensed gravitational scalars.