Results for "Lucas Hackl"

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Minimal energy cost of entanglement extractionApr 12 2019Jul 12 2019We compute the minimal energy cost for extracting entanglement from the ground state of a bosonic or fermionic quadratic system. Specifically, we find the minimal energy increase $\Delta E_{\mathrm{min}}$ in the system resulting from replacing an entangled ... More
Volume Law and Quantum Criticality in the Entanglement Entropy of Excited Eigenstates of the Quantum Ising ModelAug 27 2018Dec 03 2018Much has been learned about universal properties of entanglement entropies in ground states of quantum many-body lattice systems. Here we unveil universal properties of the average bipartite entanglement entropy of eigenstates of the paradigmatic quantum ... More
Entanglement production in bosonic systems: Linear and logarithmic growthOct 11 2017Mar 15 2018We study the time evolution of the entanglement entropy in bosonic systems with time-independent, or time-periodic, Hamiltonians. In the first part, we focus on quadratic Hamiltonians and Gaussian initial states. We show that all quadratic Hamiltonians ... More
Average eigenstate entanglement entropy of the XY chain in a transverse field and its universality for translationally invariant quadratic fermionic modelsDec 20 2018Feb 13 2019We recently showed [Phys. Rev. Lett. 121, 220602 (2018)] that the average bipartite entanglement entropy of all energy eigenstates of the quantum Ising chain exhibits a universal (for translationally invariant quadratic fermionic models) leading term ... More
Entanglement Entropy of Eigenstates of Quadratic Fermionic HamiltoniansMar 08 2017Jul 12 2017In a seminal paper [D. N. Page, Phys. Rev. Lett. 71, 1291 (1993)], Page proved that the average entanglement entropy of subsystems of random pure states is $S_{\rm ave}\simeq\ln{\cal D}_{\rm A} - (1/2) {\cal D}_{\rm A}^2/{\cal D}$ for $1\ll{\cal D}_{\rm ... More
Gaussian time dependent variational principle for the Bose-Hubbard modelJul 10 2019Jul 18 2019We systematically extend Bogoliubov theory beyond the mean field approximation of the Bose-Hubbard model in the superfluid phase. Our approach is based on the time dependent variational principle applied to the family of all Gaussian states (i.e. Gaussian ... More
Comparing efficient computation methods for massless QCD tree amplitudes: Closed Analytic Formulae versus Berends-Giele RecursionJun 11 2012Recent advances in our understanding of tree-level QCD amplitudes in the massless limit exploiting an effective (maximal) supersymmetry have led to the complete analytic construction of tree-amplitudes with up to four external quark-anti-quark pairs. ... More
Horizon complementarity in elliptic de Sitter spaceSep 23 2014Feb 03 2015We study a quantum field in elliptic de Sitter space dS_4/Z_2 - the spacetime obtained from identifying antipodal points in dS_4. We find that the operator algebra and Hilbert space cannot be defined for the entire space, but only for observable causal ... More
Gaussian TDVP for the Bose-Hubbard modelJul 10 2019We systematically extend Bogoliubov theory beyond the mean field approximation of the Bose- Hubbard model in the superfluid phase. Our approach is based on the time dependent variational principle applied to the family of all Gaussian states (i.e., Gaussian ... More
Minimal energy cost of entanglement extractionApr 12 2019May 16 2019We compute the minimal energy cost for extracting entanglement from the ground state of a bosonic or fermionic quadratic system. Specifically, we find the minimal energy increase $\Delta E_{\mathrm{min}}$ in the system resulting from replacing an entangled ... More
Circuit complexity for free fermionsMar 28 2018We study circuit complexity for free fermionic field theories and Gaussian states. Our definition of circuit complexity is based on the notion of geodesic distance on the Lie group of special orthogonal transformations equipped with a right-invariant ... More
Minimal energy cost of entanglement extractionApr 12 2019We compute the minimal energy cost for extracting entanglement from the ground state of a bosonic or fermionic quadratic system. Specifically, we find the minimal energy increase in the system resulting from replacing an entangled pair of modes, sharing ... More
Zeeman-driven Lifshitz transition: A scenario for the Fermi-surface reconstruction in YbRh2Si2Dec 01 2010The heavy-fermion metal YbRh2Si2 displays a field-driven quantum phase transition where signatures of a Fermi-surface reconstruction have been identified, often interpreted as breakdown of the Kondo effect. We argue that instead many properties of the ... More
Entanglement time in the primordial universeDec 30 2015We investigate the behavior of the entanglement entropy of space in the primordial phase of the universe before the beginning of cosmic inflation. We argue that in this phase the entanglement entropy of a region of space grows from a zero-law to an area-law. ... More
Linear growth of the entanglement entropy and the Kolmogorov-Sinai rateSep 01 2017Feb 26 2018The rate of entropy production in a classical dynamical system is characterized by the Kolmogorov-Sinai entropy rate $h_{\mathrm{KS}}$ given by the sum of all positive Lyapunov exponents of the system. We prove a quantum version of this result valid for ... More
Entanglement entropy of squeezed vacua on a latticeJul 06 2015We derive a formula for the entanglement entropy of squeezed states on a lattice in terms of the complex structure J. The analysis involves the identification of squeezed states with group-theoretical coherent states of the symplectic group and the relation ... More
Thermodynamic signatures of a fractionalized Fermi liquidJan 18 2011Several heavy-fermion metals display a quantum phase transition from an antiferromagnetic metal to a heavy Fermi liquid. In some materials, however, recent experiments seem to find that the heavy Fermi liquid phase can be directly tuned into a non-Fermi ... More
The Necklace Process: A Generating Function ApproachJan 30 2018Jul 24 2018The "necklace process", a procedure constructing necklaces of black and white beads by randomly choosing positions to insert new beads (whose color is uniquely determined based on the chosen location), is revisited. This article illustrates how, after ... More
Growing and Destroying Catalan-Stanley TreesApr 12 2017Feb 26 2018Stanley lists the class of Dyck paths where all returns to the axis are of odd length as one of the many objects enumerated by (shifted) Catalan numbers. By the standard bijection in this context, these special Dyck paths correspond to a class of rooted ... More
Loop expansion and the bosonic representation of loop quantum gravitySep 07 2016We introduce a new loop expansion that provides a resolution of the identity in the Hilbert space of loop quantum gravity on a fixed graph. We work in the bosonic representation obtained by the canonical quantization of the spinorial formalism. The resolution ... More
Squeezed vacua in loop quantum gravityMay 17 2016We introduce squeezed vacua in loop quantum gravity, a new overcomplete basis of states that contain prescribable correlations between geometric operators. We study the behavior of long-range correlations and discuss the relevance of these states for ... More
The Register Function and Reductions of Binary Trees and Lattice PathsFeb 19 2016May 11 2016The register function (or Horton-Strahler number) of a binary tree is a well-known combinatorial parameter. We study a reduction procedure for binary trees which offers a new interpretation for the register function as the maximal number of reductions ... More
Ascents in Non-Negative Lattice PathsJan 09 2018Non-negative {\L}ukasiewicz paths are special two-dimensional lattice paths never passing below their starting altitude which have only one single special type of down step. They are well-known and -studied combinatorial objects, in particular due to ... More
Reducing Simply Generated Trees by Iterative Leaf CuttingAug 01 2018We consider a procedure to reduce simply generated trees by iteratively removing all leaves. In the context of this reduction, we study the number of vertices that are deleted after applying this procedure a fixed number of times by using an additive ... More
Reductions of Binary Trees and Lattice Paths induced by the Register FunctionDec 21 2016The register function (or Horton-Strahler number) of a binary tree is a well-known combinatorial parameter. We study a reduction procedure for binary trees which offers a new interpretation for the register function as the maximal number of reductions ... More
A canonical rate-independent model of geometrically linear isotropic gradient plasticity with isotropic hardening and plastic spin accounting for the Burgers vectorMar 01 2016Apr 04 2019In this paper we propose a canonical variational framework for rate-independent phenomenological geometrically linear gradient plasticity with plastic spin. The model combines the additive decomposition of the total distortion into non-symmetric elastic ... More
A Combinatorial Identity for Rooted Labelled ForestsFeb 18 2019In this brief note a purely combinatorial proof for an identity related to rooted forests and unordered set partitions is provided. Furthermore, references that put this type of identity in the context of forest volumes are given.
Complexity and entanglement for thermofield double statesOct 11 2018Feb 15 2019Motivated by holographic complexity proposals as novel probes of black hole spacetimes, we explore circuit complexity for thermofield double (TFD) states in free scalar quantum field theories using the Nielsen approach. For TFD states at t = 0, we show ... More
A Combinatorial Identity for Rooted Labeled ForestsFeb 18 2019Jul 10 2019In this brief note a straightforward combinatorial proof for an identity directly connecting rooted forests and unordered set partitions is provided. Furthermore, references that put this type of identity in the context of forest volumes and multinomial ... More
Analysis of Bidirectional Ballot Sequences and Random Walks Ending in their MaximumMar 30 2015Oct 12 2015Consider non-negative lattice paths ending at their maximum height, which will be called admissible paths. We show that the probability for a lattice path to be admissible is related to the Chebyshev polynomials of the first or second kind, depending ... More
Fringe Analysis of Plane Trees Related to Cutting and PruningApr 04 2017Rooted plane trees are reduced by four different operations on the fringe. The number of surviving nodes after reducing the tree repeatedly for a fixed number of times is asymptotically analyzed. The four different operations include cutting all or only ... More
A statistical noise model for a class of Physically Unclonable FunctionsSep 29 2014The interest in "Physically Unclonable Function"-devices has increased rapidly over the last few years, as they have several interesting properties for system security related applications like, for example, the management of cryptographic keys. Unfortunately, ... More
Unitary perturbation theory approach to real-time evolution problemsSep 20 2008Oct 24 2008We discuss a new analytical approach to real-time evolution in quantum many-body systems. Our approach extends the framework of continuous unitary transformations such that it amounts to a novel solution method for the Heisenberg equations of motion for ... More
Nernst effect in the electron-doped cupratesJan 15 2009Jun 12 2009We calculate the normal state Nernst signal in the cuprates resulting from a reconstruction of the Fermi surface due to spin density wave order. An order parameter consistent with the reconstruction of the Fermi surface detected in electron-doped materials ... More
Reply to Comment by V. R. Shaginyan et al. on "Zeeman-Driven Lifshitz Transition: A Model for the Experimentally Observed Fermi-Surface Reconstruction in YbRh2Si2"Jun 26 2012Jul 04 2012A reply to the comment by V. R. Shaginyan et al. [Phys. Rev. Lett. 107, 279701 (2011), arXiv:1206.5372] on our article [Phys. Rev. Lett. 106, 137002 (2011), arXiv:1012.0303].
Kondo volume collapse, Kondo breakdown, and Fermi surface transitions in heavy-fermion metalsDec 13 2007Apr 25 2008The unconventional critical behavior near magnetic quantum phase transitions in various heavy-fermion metals, apparently inconsistent with the standard spin-density-wave scenario, has triggered proposals on the breakdown of the Kondo effect at the critical ... More
Stripe order and quasiparticle Nernst effect in cuprate superconductorsAug 20 2010After a brief review of current ideas on stripe order in cuprate high-temperature superconductors, we discuss the quasiparticle Nernst effect in the cuprates, with focus on its evolution in non-superconducting stripe and related nematic states. In general, ... More
On the equivalence of proportional-integral and proportional-resonant controllers with anti-windupOct 23 2016It is shown that proportional-integral (PI) control in the synchronously rotating (d, q)-reference frame and proportional-resonant (PR) control in the stationary ({\alpha}, \b{eta})-reference frame, both with anti-windup, are equivalent if and only if ... More
Modem Illumination of Monotone PolygonsMar 17 2015We study a generalization of the classical problem of the illumination of polygons. Instead of modeling a light source we model a wireless device whose radio signal can penetrate a given number $k$ of walls. We call these objects $k$-modems and study ... More
Quantum bright solitons in a quasi-one-dimensional optical latticeJan 31 2014Jun 04 2014We study a quasi-one-dimensional attractive Bose gas confined in an optical lattice with a superimposed harmonic potential by analyzing the effective one-dimensional Bose-Hubbard Hamiltonian of the system. In order to have a reliable description of the ... More
Pressure-induced magnetic transition and volume collapse in FeAs superconductors: An orbital-selective Mott scenarioDec 18 2008May 04 2009Motivated by pressure experiments on FeAs-122 superconductors, we propose a scenario based on local-moment physics to explain the simultaneous disappearance of magnetism, reduction of the unit cell volume, and decrease in resistivity. In this scenario, ... More
Maximizing Maximal Angles for Plane Straight-Line GraphsMay 25 2007Oct 12 2009Let $G=(S, E)$ be a plane straight-line graph on a finite point set $S\subset\R^2$ in general position. The incident angles of a vertex $p \in S$ of $G$ are the angles between any two edges of $G$ that appear consecutively in the circular order of the ... More
Safe Recursion on Notation into a Light Logic by LevelsMay 04 2010We embed Safe Recursion on Notation (SRN) into Light Affine Logic by Levels (LALL), derived from the logic L4. LALL is an intuitionistic deductive system, with a polynomial time cut elimination strategy. The embedding allows to represent every term t ... More
Real Time Evolution in Quantum Many-Body Systems With Unitary Perturbation TheorySep 13 2007Aug 26 2008We develop a new analytical method for solving real time evolution problems of quantum many-body systems. Our approach is a direct generalization of the well-known canonical perturbation theory for classical systems. Similar to canonical perturbation ... More
Reply to Comment by S. Friedemann et al. on "Zeeman-Driven Lifshitz Transition: A Model for the Experimentally Observed Fermi-Surface Reconstruction in YbRh2Si2"Jul 04 2012A reply to the comment by S. Friedemann et al. [arXiv:1207.0536] on our article [Phys. Rev. Lett. 106, 137002 (2011), arXiv:1012.0303].
Nernst effect anisotropy as a sensitive probe of Fermi surface distortions from electron-nematic orderSep 25 2009Dec 01 2009We analyze the thermoelectric response in layered metals with spontaneously broken rotation symmetry. We identify the anisotropy of the quasiparticle Nernst signal as an extremely sensitive probe of Fermi surface distortions characteristic of the ordered ... More
Frustrated Magnetism from Local Moments in FeSeDec 22 2018Mar 18 2019We investigate properties of a spin-1 Heisenberg model with extended and biquadratic interactions, which captures crucial aspects of the low energy physics in FeSe. While we show that the model exhibits a rich phase diagram with four different magnetic ... More
From Lock Freedom to Progress Using Session TypesDec 10 2013Inspired by Kobayashi's type system for lock freedom, we define a behavioral type system for ensuring progress in a language of binary sessions. The key idea is to annotate actions in session types with priorities representing the urgency with which such ... More
Linear lambda Calculus with Explicit Substitutions as Proof-Search in Deep InferenceNov 16 2010May 26 2011SBV is a deep inference system that extends the set of logical operators of multiplicative linear logic with the non commutative operator Seq. We introduce the logical system SBVr which extends SBV by adding a self-dual atom-renaming operator to it. We ... More
A Discussion on the Heisenberg Uncertainty Principle from the Perspective of Special RelativityJan 09 2015Sep 16 2016In this note, we consider the implications of the Heisenberg uncertainty principle (HUP) when computing uncertainties that affect the main dynamical quantities, from the perspective of special relativity. Using the well-known formula for propagating statistical ... More
Conformal metrics on R^{2m} with constant Q-curvature and large volumeFeb 06 2012We study conformal metrics on R^{2m} with constant Q-curvature and finite volume. When m=3 we show that there exists V* such that for any V\in [V*,\infty) there is a conformal metric g on R^{6} with Q_g = Q-curvature of S^6, and vol(g)=V. This is in sharp ... More
Classification of solutions to the higher order Liouville's equation on R^{2m}Jan 17 2008We classify the solutions to the equation (- \Delta)^m u=(2m-1)!e^{2mu} on R^{2m} giving rise to a metric g=e^{2u}g_{R^{2m}} with finite total $Q$-curvature in terms of analytic and geometric properties. The analytic conditions involve the growth rate ... More
Discrete bright solitons in Bose-Einstein condensates and dimensional reduction in quantum field theoryNov 01 2014Nov 04 2014We first review the derivation of an effective one-dimensional (1D) discrete nonpolynomial Schr\"odinger equation from the continuous 3D Gross-Pitaevskii equation with transverse harmonic confinement and axial periodic potential. Then we study the bright ... More
Two-dimensional quasi-ideal Fermi gas with Rashba spin-orbit couplingNov 16 2013Nov 22 2013We investigate the zero-temperature properties of a quasi-ideal Fermi gas with Rashba spin-orbit coupling. We find that the spin-orbit term strongly affects the speeds of zero sound and first sound in the Fermi gas, due to the presence of a third-order ... More
Contact intensity and extended hydrodynamics in the BCS-BEC crossoverOct 12 2012In the first part of this chapter we analyze the contact intensity $C$, which has been introduced by Tan [Ann. Phys. 323, 2952 (2008)] and appears in several physical observables of the strongly correlated two-component Fermi gas. We calculate the contact ... More
Supersonic and subsonic shock waves in the unitary Fermi gasOct 03 2011We investigate shock waves in the unitary Fermi gas by using the zero-temperature equations of superfluid hydrodynamics. We obtain analytical solutions for the dynamics of a localized perturbation of the uniform gas. These supersonic bright and subsonic ... More
Triaxial Bright Solitons in Bose-Condensed Atomic VaporsJul 25 2004The properties of triaxial bright solitons (TBSs) made of attractive Bose-Einstein condensed atoms under transverse anisotropic harmonic confinement are investigated by using a variational approach. We show that these metastable TBSs change their shape ... More
Statistical Mechanics of a Trapped Bose-Einstein CondensateMar 26 1998Bose-Einstein condensation (BEC) in a gas has now been achieved. Alkali atoms ($^{87}Rb$, $^{23}Na$ and $^{7}Li$) have been cooled to the point of condensation (temperature of 100 nK) using laser cooling and trapping, followed by magnetic trapping and ... More
Review on 'Integrability of the S-Matrix vs Integrability of the Hamiltonian' by C. Jung and T.H. SeligmanDec 16 1997We review the paper 'Integrability of the S-Matrix vs Integrability of the Hamiltonian' by C. Jung and T.H. Seligman (Phys. Rep. 285, 77-141 (1997)). This paper deals with the connection between the integrability of the scattering matrix $S$ and the integrability ... More
Quantum Transition from Order to Chaos in the Nuclear Shell ModelJul 21 1997We discuss the role of quantum chaos in atomic nuclei. After reviewing the basic assumptions of the nuclear shell model, we analyze the spectral statistics of the energy levels obtained with realistic shell-model calculations in the fp shell. In particular, ... More
On the Torus Quantization of Two Anyons with Coulomb Interaction in a Magnetic FieldApr 10 1997We study two anyons with Coulomb interaction in a uniform magnetic field $B$. By using the torus quantization we obtain the modified Landau and Zeeman formulas for the two anyons. Then we derive a simple algebraic equation for the full spectral problem ... More
Multi Solitons of a Bose-Einstein Condensate in a Three-Dimensional RingNov 03 2005A Bose-Einstein Condensate (BEC) made of alkali-metal atoms at ultra-low temperatures is well described by the three-dimensional cubic nonlinear Schr\"odinger equation, the so-called Gross-Pitaevskii equation (GPE). Here we consider an attractive BEC ... More
Particles and Anti-Particles in a Relativistic Bose CondensateJul 22 2002We study the Bose-Einstein condensation (BEC) for a relativistic ideal gas of bosons. In the framework of canonical thermal field theory, we analyze the role of particles and anti-particles in the determination of BEC transition temperature. At the BEC ... More
Embedding right-angled Artin groups into graph braid groupsJun 13 2005Apr 02 2010We construct an embedding of any right-angled Artin group $G(\Delta)$ defined by a graph $\Delta$ into a graph braid group. The number of strands required for the braid group is equal to the chromatic number of $\Delta$. This construction yields an example ... More
Time-dependent Hypercritical Accretion onto Black HolesDec 10 1996Results are presented from a time-dependent, numerical investigation of super-Eddington spherical accretion onto black holes with different initial conditions. We have studied the stability of stationary solutions, the non-linear evolution of shocked ... More
Detections of millisecond pulsars with the Fermi Large Area TelescopeOct 25 2009The Fermi observatory was launched on June 11, 2008. It hosts the \emph{Large Area Telescope} (LAT), sensitive to $\gamma$-ray photons from 20 MeV to over 300 GeV. When the LAT began its activity, nine young and energetic pulsars were known in $\gamma$ ... More
Comment on "Bell's Theorem without Inequalities and without Alignments"Sep 20 2004In this Comment we show that Cabello's proof of Bell's theorem without inequalities [Phys. Rev. Lett. 91, 230403 (2003)] does not exhibit two of the three "remarkable properties" which the proof is claimed to possess. More precisely it is our purpose ... More
Photometric stellar parameters for asteroseismology and Galactic studiesSep 08 2014Asteroseismology has the capability of delivering stellar properties which would otherwise be inaccessible, such as radii, masses and thus ages of stars. When coupling this information with classical determinations of stellar parameters, such as metallicities, ... More
Covariant Anomalies and Functional DeterminantsDec 06 1993We analize the algebraic structure of consistent and covariant anomalies in gauge and gravitational theories: using a complex extension of the Lie algebra it is possible to describe them in a unified way. Then we study their representations by means of ... More
LFV in Models with A4 Flavour SymmetryNov 21 2008The approximated tri-bimaximal mixing observed in the neutrino oscillations is a particular feature of a class of models characterized by the spontaneously broken horizontal flavour symmetry A4. In this paper, it is presented an analysis on the predictions ... More
Theoretical Models for Neutrino MassesMay 25 2012The recent measurements of the neutrino reactor angle require a re-examination of flavour models based on discrete groups. Indeed, when these models deal with the Tri-Bimaximal, the Bimaximal and the Golden Ratio mixing patterns, some tensions arise in ... More
R-symmetry breaking, runaway directions and global symmetries in O'Raifeartaigh modelsMay 14 2007We discuss O'Raifeartaigh models with general R-charge assignments, introduced by Shih to break R-symmetry spontaneously. We argue that most of these models have runaway directions related to the R-symmetry. In addition, we study the simplest model with ... More
Theoretical approaches to the physics of spectral line polarizationMar 28 2011Due to the continuous developments in polarimetric instrumentation, which will become even more dramatic in the near future with the availability of new generation solar telescopes, we are now severely confronted with a variety of new detailed observations ... More
Weakly-Interacting Massive Particles in Torsionally-Gravitating Dirac TheoryNov 16 2012Jul 05 2013We shall consider the problem of Dark Matter in torsion gravity with Dirac matter fields; we will consider the fact that if WIMPs in a bath are allowed to form condensates then torsional effects may be relevant even at galactic scales: we show that torsionally-gravitating ... More
A Torsional Model of LeptonsAug 22 2012Dec 27 2012Quite recently it was shown that torsion induces interactions among leptons that are identical to the weak interactions of leptons of the Weinberg standard model, if it is in terms of leptonic bound states that the bosonic sector is built: here we obtain ... More
Conformal Gravity with the most general ELKO MatterJan 13 2011Apr 10 2014Recently we have constructed the conformal gravity with metric and torsion, finding the gravitational field equations that give the conservation laws and trace condition; in the present paper we apply this theory to the case of ELKO matter field, proving ... More
Causality for ELKOsNov 27 2009Sep 10 2010The importance for cosmology of the recently introduced ELKOs requires our deepest understanding of them and of all of their fundamental properties. Among these fundamental properties, a special one is causality: in the present paper, we show that causality ... More
Higher-Order Theories of GravitationJun 16 2008Apr 26 2011We study higher-order theories of gravitation; in particular, we will focus our attention on the second-order theory, in which conformal symmetry can be implemented.
On a purely geometric approach to the Dirac matter field and its quantum propertiesOct 03 2012May 08 2014We consider the most general axial torsion completion of gravity with electrodynamics for $\frac{1}{2}$-spin spinors in an $8$-dimensional representation of the Dirac matter field: this theory will allow to define antimatter as matter with all quantum ... More
On moduli and effective theory of N=1 warped flux compactificationsFeb 24 2009May 28 2009The moduli space of N=1 type II warped compactions to flat space with generic internal fluxes is studied. Using the underlying integrable generalized complex structure that characterizes these vacua, the different deformations are classified by H-twisted ... More
Semiclassical strings on confining backgroundsMar 31 2005This paper discusses some results on semiclassical string configurations lying in the IR sector of supergravity backgrounds dual to confining gauge theories. On the gauge theory side, the string states we analyse correspond to Wilson loops, glueballs ... More
Galilean symmetry in generalized abelian Schrödinger-Higgs models with and without gauge field interactionMar 16 2015Oct 14 2015We consider a generalization of nonrelativistic Schr\"odinger-Higgs Lagrangian by introducing a nonstandard kinetic term. We show that this model is Galilean invariant, we construct the conserved charges associated to the symmetries and realize the algebra ... More
Singular soliton solution in the Chern-Simons-CP(1) modelApr 26 2011Sep 13 2011We show that the Chern-Simons-CP(1) model can support a singular soliton solution in which the magnetic field is a Dirac delta.
The Limiting Shape for Drifted Internal Diffusion Limited Aggregation is a True Heat BallFeb 09 2012Feb 17 2013We build the iDLA cluster using drifted random walks, and study the limiting shapes they exhibit, with the help of sandpile models. For constant drift, the normalised cluster converges to a canonical shape S, which can be termed a true heat ball, in that ... More
Lagrangian mechanics on Lie groups: a pedagogical approachNov 05 2011We describe a new method to formulate classical Lagrangian mechanics on a finite-dimensional Lie group. This new approach is much more pedagogical than many previous treatments of the subject, and it directly introduces students to generator matrices ... More
Lower complexity bounds for positive contactomorphismsFeb 19 2016Let $S^*Q$ be the spherization of a closed connected manifold of dimension at least two. Consider a contactomorphism $\varphi$ that can be reached by a contact isotopy that is everywhere positively transverse to the contact structure. In other words, ... More
Asymptotic Equation for Zeros of Hermite Polynomials from the Holstein-Primakoff RepresentationJun 01 2015Jun 05 2015The Holstein-Primakoff representation for spin systems is used to derive expressions with solutions that are conjectured to be the zeros of Hermite polynomials $H_n(x)$ as $n \rightarrow \infty$. This establishes a correspondence between the zeros of ... More
A solvable model of the evolutionary loopJun 19 1998A model for the evolution of a finite population in a rugged fitness landscape is introduced and solved. The population is trapped in an evolutionary loop, alternating periods of stasis to periods in which it performs adaptive walks. The dependence of ... More
Lehmer problem and Drinfeld modulesFeb 01 2013Jan 21 2015We propose a lower bound estimate in Dobrowolski's style of the canonical height on a certain family of Drinfeld modules of characteristic 0, including under some hypothesis on their degree and their base field, the complex multiplication case, extending ... More
Phantom energy mediates a long-range repulsive forceSep 22 2004Oct 14 2004Scalar field models with non-standard kinetic terms have been proposed in the context of k-inflation, of Born-Infeld lagrangians, of phantom energy and, more in general, of low-energy string theory. In general, scalar fields are expected to couple to ... More
Schröder partitions, Schröder tableaux and weak poset patternsJun 21 2016We introduce the notions of Schr\"oder shape and of Schr\"oder tableau, which provide some kind of analogs of the classical notions of Young shape and Young tableau. We investigate some properties of the partial order given by containment of Schr\"oder ... More
Wonderful models for toric arrangementsDec 30 2009Feb 09 2011We build a wonderful model for toric arrangements. We develop the "toric analog" of the combinatorics of nested sets, which allows to define a family of smooth open sets covering the model. In this way we prove that the model is smooth, and we give a ... More
Torsion Gravity for Dirac ParticlesNov 25 2016We elucidate the role of torsion in gravity by showing how Dirac matter fields have distributions that are stable and localized and as such they can be seen as particles.
The KSBA compactification of the moduli space of $D_{1,6}$-polarized Enriques surfacesAug 08 2016Oct 11 2016We describe the moduli compactification by stable pairs of a $4$-dimensional family of Enriques surfaces, which arise as the $\mathbb{Z}_2^2$-covers of the blow up of $\mathbb{P}^2$ at three general points branched along a configuration of three pairs ... More
Quasilinear parabolic stochastic evolution equations via maximal $ L^{p} $-regularityNov 28 2016We study the Cauchy problem for an abstract quasilinear stochastic parabolic evolution equation on a Banach space driven by a cylindrical Brownian motion. We prove existence and uniqueness of a local strong solution up to a maximal stopping time, that ... More
Dirac-Jacobi BundlesFeb 18 2015Feb 10 2016We show that a suitable notion of Dirac-Jacobi structure on a generic line bundle $L$ is provided by Dirac structures in the omni-Lie algebroid of $L$. Dirac-Jacobi structures on line bundles generalize Wade's $\mathcal E^1 (M)$-Dirac structures and unify ... More
Search for Sterile Neutrinos at Long and Short BaselinesApr 22 2016Neutrino physics is currently suffering from lack of knowledge from at least four major ingredients. One of them is the presence or not of new sterile neutrino states at the mass scale of around 1 eV. Settling this point should be the highest priority ... More
Looking for ovoids of the Hermitian surface: a computational approachOct 09 2012In this note we present a computational approach to the construction of ovoids of the Hermitian surface and show some related experimental results.
Zero Energy of Plane-Waves for ELKOsAug 02 2010Feb 23 2011We consider the ELKO field in interaction through contorsion with its own spin density, and we investigate the form of the consequent autointeractions; to do so we take into account the high-density limit and find plane wave solutions: such plane waves ... More
Torsionally-gravitating charged matter fields and quantaMar 17 2015Jan 26 2016In the present article we shall consider the torsional completion of a gravitational background that is filled with electrodynamically interacting material fields, taken to be of fermionic type, eventually deriving properties like the impossibility of ... More