Almost Cosymplectic $$(k,\mu )$$-metrics as $$\eta$$-Ricci Solitons

Abstract In this paper, we study $$\eta$$ ? -Ricci solitons on almost cosymplectic $$(k,\mu )$$ ( k , ? ) -manifolds. As an application, it is proved that if -metric with $$k<0$$ < 0 represents a Ricci soliton, then the potential vector field of soliton strict infinitesimal contact transformation, and corresponding manifold locally isometric to Lie group whose local structure determined completely by . addition, concrete example constructed illustrate above result.