  Besides scalarized black holes and wormholes, Einstein-scalar-Gauss-Bonnet
theories allow also for particle-like solutions. The scalar field of these
particle-like solutions diverges at the origin, akin to the divergence of the
Coulomb potential at the location of a charged particle. However, these
particle-like solutions possess a globally regular metric, and their effective
stress energy tensor is free from pathologies, as well. We determine the domain
of existence for particle-like solutions in a number of
Einstein-scalar-Gauss-Bonnet theories, considering dilatonic and power-law
coupling functions, and we analyze the physical properties of the solutions.
Interestingly, the solutions may possess pairs of lightrings, and thus
represent ultra-compact objects. We determine the location of these lightrings,
and study the effective potential for the occurrence of echoes in the
gravitational-wave spectrum. We also address the relation of these
particle-like solutions to the respective wormhole and black-hole solutions,
and clarify the limiting procedure to recover the Fisher solution (also known
as Janis-Newman-Winicourt-Wyman solution).
