Title: Nijenhuis deformations of Poisson algebras and $F$-manifold algebras

Abstract: The notion of pre-Poisson algebras was introduced by Aguiar in his study of zinbiel algebras and pre-Lie algebras. In this paper, we first introduce NS-Poisson algebras as a generalization of both Poisson algebras and pre-Poisson algebras. An NS-Poisson algebra has an associated sub-adjacent Poisson algebra. We show that a Nijenhuis operator on a Poisson algebra deforms the structure into an NS-Poisson algebra. The semi-classical limit of an NS-algebra deformation and a suitable filtration of an NS-algebra produce NS-Poisson algebras. On the other hand, $F$-manifold algebras were introduced by Dotsenko as the underlying algebraic structure of $F$-manifolds. We also introduce NS-$F$-manifold algebras as a simultaneous generalization of NS-Poisson algebras, $F$-manifold algebras and pre-$F$-manifold algebras. In the end, we show that Nijenhuis deformations of $F$-manifold algebras and the semi-classical limits of NS-pre-Lie algebra deformations have NS-$F$-manifold algebra structures.