17 citations · 47 across the 24 of their papers we have counts for
26 papers
An affine Birkhoff-Kellogg type result in product spaces and its application to differential systems
Alessandro Calamai, Gennaro Infante, Giuseppe Antonio Veltri
We prove a version of the Birkhoff-Kellogg theorem in product spaces, under affine transformations. This is a fairly natural framework that arises when dealing with parameter-depen…
Birkhoff-Kellogg type results in product spaces and their application to differential systems
Alessandro Calamai, Gennaro Infante, Jorge Rodríguez-López
We provide a new version of the well-known Birkhoff-Kellogg invariant-direction Theorem in product spaces. Our results concern operator systems and give the existence of component-…
A new construction for Melnikov chaos in piecewise-smooth planar systems
Alessandro Calamai, Matteo Franca, Michal Pospisil
In this paper we consider a piecewise smooth -dimensional system \[ \dot{\vec{x}}=\vec{g} (\vec{x})+\varepsilon\vec{g}(t,\vec{x},\varepsilon) \] where is a small…
Forced oscillations for generalized -Laplacian equations with Carathéodory perturbations
Alessandro Calamai, Maria Patrizia Pera, Marco Spadini
Using topological methods, we study the structure of the set of forced oscillations of a class of parametric, implicit ordinary differential equations with a generalized -Laplac…
Some contributions on Melnikov chaos for smooth and piecewise-smooth planar systems: "trajectories chaotic in the future"
Alessandro Calamai, Matteo Franca, Michal Pospisil
We consider a -dimensional autonomous system subject to a -periodic perturbation, i.e. We assume…
On the dynamics of non-autonomous systems in a~neighborhood of a~homoclinic trajectory
Alessandro Calamai, Matteo Franca, Michal Pospisil
This article is devoted to the study of a -dimensional piecewise smooth (but possibly) discontinuous dynamical system, subject to a non-autonomous perturbation; we assume that t…
On the solvability of parameter-dependent elliptic functional BVPs on annular-like domains
Alessandro Calamai, Gennaro Infante
We investigate the existence of nontrivial solutions of parameter-dependent elliptic equations with deviated argument in annular-like domains in , with , s…
A Birkhoff-Kellogg type theorem for discontinuous operators with applications
Alessandro Calamai, Gennaro Infante, Jorge Rodríguez-López
By means of fixed point index theory for multi-valued maps, we provide an analogue of the classical Birkhoff--Kellogg Theorem in the context of discontinuous operators acting on af…
Nontrivial solutions of a parameter-dependent heat flow problem with deviated arguments
Alessandro Calamai, Gennaro Infante
By means of a recent Birkhoff-Kellogg type theorem set in affine cones, we discuss the solvability of a parameter-dependent thermostat problem subject to deviated arguments. We ill…
On fourth order retarded equations with functional boundary conditions: a unified approach
Alessandro Calamai, Gennaro Infante
By means of a recent Birkhoff-Kellogg type theorem, we discuss the solvability of a fairly general class of parameter-dependent fourth order retarded differential equations subject…
Periodic perturbations of a class of scalar second order functional differential equations
Alessandro Calamai, Maria Patrizia Pera, Marco Spadini
We study, by means of a topological approach, the forced oscillations of second order functional retarded differential equations subject to periodic perturbations. We consider a de…
An affine Birkhoff--Kellogg type result in cones with applications to functional differential equations
Alessandro Calamai, Gennaro Infante
In this short note we prove, by means of classical fixed point index, an affine version of a Birkhoff--Kellogg type theorem in cones. We apply our result to discuss the solvability…
Global persistence of the unit eigenvectors of perturbed eigenvalue problems in Hilbert spaces: the odd multiplicity case
Pierluigi Benevieri, Alessandro Calamai, Massimo Furi +1
We study the persistence of eigenvalues and eigenvectors of perturbed eigenvalue problems in Hilbert spaces. We assume that the unperturbed problem has a nontrivial kernel of odd d…
Nonzero positive solutions of fractional Laplacian systems with functional terms
Stefano Biagi, Alessandro Calamai, Gennaro Infante
We study the existence of non-zero positive solutions of a class of systems of differential equations driven by fractional powers of the Laplacian. Our approach is based on the not…
A degree associated to linear eigenvalue problems in Hilbert spaces and applications to nonlinear spectral theory
Pierluigi Benevieri, Alessandro Calamai, Massimo Furi +1
We extend to the infinite dimensional context the link between two completely different topics recently highlighted by the authors: the classical eigenvalue problem for real square…
Boundary value problems associated with singular strongly nonlinear equations with functional terms
Stefano Biagi, Alessandro Calamai, Cristina Marcelli +1
We study boundary value problems associated with singular, strongly nonlinear differential equations with functional terms of type $$\big(Φ(k(t)\,x'(t))\big)' + f(t,\mathcal{G}_x(t…
Global persistence of the unit eigenvectors of perturbed eigenvalue problems in Hilbert spaces
Pierluigi Benevieri, Alessandro Calamai, Massimo Furi +1
We consider the nonlinear eigenvalue problem , , where are real parameters, are bounded linear operators…
The Brouwer degree associated to classical eigenvalue problems and applications to nonlinear spectral theory
Pierluigi Benevieri, Alessandro Calamai, Massimo Furi +1
Thanks to a connection between two completely different topics, the classical eigenvalue problem in a finite dimensional real vector space and the Brouwer degree for maps between o…
Nonzero positive solutions of elliptic systems with gradient dependence and functional BCs
Stefano Biagi, Alessandro Calamai, Gennaro Infante
We discuss, by topological methods, the solvability of systems of second-order elliptic differential equations subject to functional boundary conditions under the presence of gradi…
Existence results for boundary value problems associated with singular strongly nonlinear equations
Stefano Biagi, Alessandro Calamai, Francesca Papalini
We consider a strongly nonlinear differential equation of the following general type where is a Cara…
Nontrivial solutions of boundary value problems for second order functional differential equations
Alessandro Calamai, Gennaro Infante
In this paper we present a theory for the existence of multiple nontrivial solutions for a class of perturbed Hammerstein integral equations. Our methodology, rather than to work d…
Periodic solutions of semi-explicit differential-algebraic equations with time-dependent constraints
Luca Bisconti, Alessandro Calamai, Marco Spadini
In this paper we investigate the properties of the set of T-periodic solutions of semi-explicit parametrized Differential-Algebraic Equations with non-autonomous constraints of a p…
Periodic perturbations of constrained motion problems on a class of implicitly defined manifolds
Alessandro Calamai, Marco Spadini
We study forced oscillations on differentiable manifolds which are globally defined as the zero set of appropriate smooth maps in some Euclidean spaces. Given a T-periodic perturba…
Branches of forced oscillations for a class of constrained ODEs: a topological approach
Alessandro Calamai, Marco Spadini
We apply topological methods to obtain global continuation results for harmonic solutions of some periodically perturbed ordinary differential equations on a -dimensional differ…