13 citations · 115 across the 24 of their papers we have counts for
24 papers
Schrödinger operators with multiple Aharonov-Bohm fluxes
Michele Correggi, Davide Fermi
We study the Schrödinger operator describing a two-dimensional quantum particle moving in presence of Aharonov-Bohm magnetic fluxes. We classify all the self-adjo…
Rigorous derivation of the Efimov effect in a simple model
Davide Fermi, Daniele Ferretti, Alessandro Teta
We consider a system of three identical bosons in with two-body zero-range interactions and a three-body hard-core repulsion of a given radius . Using a quadrat…
Quadratic forms for Aharonov-Bohm Hamiltonians
Davide Fermi
We consider a charged quantum particle immersed in an axial magnetic field, comprising a local Aharonov-Bohm singularity and a regular perturbation. Quadratic form techniques are u…
Periodic striped states in Ising models with dipolar interactions
Davide Fermi, Alessandro Giuliani
We review the problem of determining the ground states of 2D Ising models with nearest neighbor ferromagnetic and dipolar interactions, and prove a new result supporting the conjec…
A note on "Algebraic approach to Casimir force between two -like potentials" (K. Ziemian, Ann. Henri Poincaré, Online First, 2021)
Davide Fermi, Livio Pizzocchero
We comment on the recent work [1], and on its relations with our papers [2,3] cited therein. In particular we show that, contrarily to what stated in [1], the Casimir energy densit…
Vacuum polarization with zero-range potentials on a hyperplane
Davide Fermi
The quantum vacuum fluctuations of a neutral scalar field induced by background zero-range potentials concentrated on a flat hyperplane of co-dimension in -dimensional M…
The semi-classical limit with a delta-prime potential
Claudio Cacciapuoti, Davide Fermi, Andrea Posilicano
We consider the quantum evolution of a Gaussian coherent state localized close to the classical state $ξ\e…
Magnetic Perturbations of Anyonic and Aharonov-Bohm Schrödinger Operators
Michele Correggi, Davide Fermi
We study the Hamiltonian describing two anyons moving in a plane in presence of an external magnetic field and identify a one-parameter family of self-adjoint realizations of the c…
The semiclassical limit on a star-graph with Kirchhoff conditions
Claudio Cacciapuoti, Davide Fermi, Andrea Posilicano
We consider the dynamics of a quantum particle of mass on a -edges star-graph with Hamiltonian and Kirchhoff conditions in the vertex. We describe…
Integrable scalar cosmologies with matter and curvature
Davide Fermi, Massimo Gengo, Livio Pizzocchero
We show that several integrable (i.e., exactly solvable) scalar cosmologies considered by Fré, Sagnotti and Sorin (Nuclear Physics \textbf{B 877}(3) (2013), 1028--1106) can be gene…
The Casimir energy anomaly for a point interaction
Davide Fermi
The Casimir energy for a massless, neutral scalar field in presence of a point interaction is analyzed using a general zeta-regularization approach developed in earlier works. In a…
The semi-classical limit with delta potentials
Claudio Cacciapuoti, Davide Fermi, Andrea Posilicano
We consider the semi-classical limit of the quantum evolution of Gaussian coherent states whenever the Hamiltonian is given, as sum of quadratic forms, by $\mathsf H= -…
On the necessity of phantom fields for solving the horizon problem in scalar cosmologies
Davide Fermi, Massimo Gengo, Livio Pizzocchero
We discuss the particle horizon problem in the framework of spatially homogeneous and isotropic scalar cosmologies. To this purpose we consider a Friedmann-Lemaitre-Robertson-Walke…
Some remarks on a new exotic spacetime for time travel by free fall
Davide Fermi
This work is essentially a review of a new spacetime model with closed causal curves, recently presented in another paper (Class. Quantum Grav. \textbf{35}(16) (2018), 165003). The…
On inverses of Krein's Q-functions
Claudio Cacciapuoti, Davide Fermi, Andrea Posilicano
Let be the self-adjoint operator defined by the -function through the Krein-like resolvent formula $$(-A_{Q}+z)^{-1}= (-A_{0}+z)^{-1}+G_{z}WQ_{z}^{-1}…
Scattering from local deformations of a semitransparent plane
Claudio Cacciapuoti, Davide Fermi, Andrea Posilicano
We study scattering for the couple of Schrödinger operators in formally defined as and , , w…
A time machine for free fall into the past
Davide Fermi, Livio Pizzocchero
Inspired by some recent works of Tippett-Tsang and Mallary-Khanna-Price, we present a new spacetime model containing closed timelike curves (CTCs). This model is obtained postulati…
Local Casimir Effect for a Scalar Field in Presence of a Point Impurity
Davide Fermi, Livio Pizzocchero
The Casimir effect for a scalar field in presence of delta-type potentials has been investigated for a long time in the case of surface delta functions, modelling semi-transparent…
Relative-Zeta and Casimir energy for a semitransparent hyperplane selecting transverse modes
Claudio Cacciapuoti, Davide Fermi, Andrea Posilicano
We study the relative zeta function for the couple of operators and , where is the free unconstrained Laplacian in () and is th…
Local zeta regularization and the scalar Casimir effect IV. The case of a rectangular box
Davide Fermi, Livio Pizzocchero
Applying the general framework for local zeta regularization proposed in Part I of this series of papers, we compute the renormalized vacuum expectation value of several observable…
Local zeta regularization and the scalar Casimir effect III. The case with a background harmonic potential
Davide Fermi, Livio Pizzocchero
Applying the general framework for local zeta regularization proposed in Part I of this series of papers, we renormalize the vacuum expectation value of the stress-energy tensor (a…
Local zeta regularization and the scalar Casimir effect II. Some explicitly solvable cases
Davide Fermi, Livio Pizzocchero
In Part I of this series of papers we have described a general formalism to compute the vacuum effects of a scalar field via local (or global) zeta regularization. In the present P…
Local zeta regularization and the scalar Casimir effect I. A general approach based on integral kernels
Davide Fermi, Livio Pizzocchero
This is the first one of a series of papers about zeta regularization of the divergences appearing in the vacuum expectation value (VEV) of several local and global observables in…
Local zeta regularization and the Casimir effect
Davide Fermi, Livio Pizzocchero
In this paper, whose aims are mainly pedagogical, we illustrate how to use the local zeta regularization to compute the stress-energy tensor of the Casimir effect. Our attention is…