Alessandro Portaluri

Morse theory for a fourth order elliptic equation with exponential nonlinearity (2009)

Abatangelo, Laura, Portaluri, Alessandro

In this paper we compute the Leray Schauder degree for a fourth order elliptic boundary value problem with exponential nonlinearity and Navier boundary condition. This will be made by proving a...

A $K$-theoretical invariant and bifurcation for a parameterized family of functionals (2009)

Portaluri, Alessandro

For a family of functionals defined on a Hilbert manifold and smoothly depending on a compact finite dimensional manifold, we give a sufficient condition on the parameter space in such a way the...

Brief communication. An indefinite Sturm theory (2008)

Portaluri, Alessandro

Sturm theory for second order differential equations was generalized to systems and higher order equations with positive leading coefficient by several authors. Here we propose a Sturm oscillation...

The homology of path spaces and Floer homology with conormal boundary conditions (2008)

Abbondandolo, Alberto, Portaluri, Alessandro, Schwarz, Matthias

We define the Floer complex for Hamiltonian orbits on the cotangent bundle of a compact manifold satisfying non-local conormal boundary conditions. We prove that the homology of this chain complex is...

Maslov index for Hamiltonian systems (2008)

Alessandro Portaluri

The aim of this article is to give an explicit formula for computing the Maslov index of the fundamental solutions of linear autonomous Hamiltonian systems in terms of the Conley-Zehnder index and...

The homology of path spaces and Floer homology with conormal boundary conditions (2008)

Abbondandolo, Alberto, Portaluri, Alessandro, Schwarz, Matthias

We define the Floer complex for Hamiltonian orbits on the cotangent bundle of a compact manifold satisfying non-local conormal boundary conditions. We prove that the homology of this chain complex is...

On the dihedral n-body problem (2007)

Ferrario, Davide L., Portaluri, Alessandro

Consider n=2l>=4 point particles with equal masses in space, subject to the following symmetry constraint: at each instant they form an orbit of the dihedral group D_l, where D_l is the group of...

A generalized Sturm theory for indefinite elliptic systems (2007)

Portaluri, Alessandro

The goal of this paper is to give a generalization of the Sturm's Oscillation and Comparison theorem in the case of formally selfadjoint ordinary differential operator of even order having strongly...

Maslov index of Hamiltonian systems (2004)

Portaluri, Alessandro

The aim of this paper is to give an explicit formula in order to compute the Maslov index of the fundamental solution of a linear autonomous Hamiltonian system, in terms of the Conley-Zehnder index...

A Morse Index Theorem and bifurcation for perturbed geodesics on Semi-Riemannian Manifolds (2003)

Musso, Monica, Pejsachowicz, Jacobo, Portaluri, Alessandro

Perturbed geodesics are trajectories of particles moving on a semi-Riemannian manifold in the presence of a potential. Our purpose here is to extend to perturbed geodesics on semi-Riemannian...

Spectral Flow, Maslov Index and Bifurcation of semi-Riemannian Geodesics (2002)

Piccione, Paolo, Portaluri, Alessandro, Tausk, Daniel V.

We give a functional analytical proof of the equality between the Maslov index of a semi-Riemannian geodesic and the spectral flow of the path of self-adjoint Fredholm operators obtained from the...