In this paper we investigate the approximation of continuous functions on Wasserstein space by smooth functions, with smoothness meant in sense Lions differentiability. particular, case a Lipschitz function are able to construct sequence infinitely differentiable having same constant as original function. This solves an open problem raised [12]. For (resp. twice) continuously function, show tha...

In this paper, under appropriate oscillating behaviours of the nonlinear term, we prove some multiplicity results for a class of nonlinear fractional equations. These problems have a variational structure and we find three solutions for them by exploiting an abstract result for smooth functionals defined on a reflexive Banach space. To make the nonlinear methods work, some careful analysis of t...

A manifold with a smooth action of a Lie group G is called G-manifold. In this paper we consider a complete Riemannian manifold M with the action of a closed and connected Lie subgroup G of the isometries. The dimension of the orbit space is called the cohomogeneity of the action. Manifolds having actions of cohomogeneity zero are called homogeneous. A classic theorem about Riemannian manifolds...

In this paper we study very smooth points of Banach spaces with special emphasis on spaces of operators. We show that when the space of compact operators is an M-ideal in the space of bounded operators, a very smooth operator T attains its norm at a unique vector x (up to a constant multiple) and T (x) is a very smooth point of the range space. We show that if for every equivalent norm on a Ban...

We consider the problem of defining the structure of a smoothmanifold on the various spaces of piecewise-smooth loops in a smooth finite dimensional manifold. We succeed for a particular type of piecewise-smooth loops. We also examine the action of the diffeomorphism group of the circle. It is not a useful action on the manifold that we define. We consider how one might fix this problem and con...