Results for "Xavier Roca-Maza"

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Coulomb Energy Density Functionals for Nuclear Systems: Recent Studies of Coulomb Exchange and Correlation FunctionalsJul 10 2019The Coulomb exchange and correlation energy density functionals for electron systems are applied to nuclear systems. It is found that the exchange functionals in the generalized gradient approximation provide agreements with the exact-Fock energy with ... More
The nuclear symmetry energy and other isovector observables from the point of view of nuclear structureApr 08 2015In this contribution, we review some works related with the extraction of the symmetry energy parameters from isovector nuclear excitations, like the giant resonances. Then, we move to the general issue of how to assess whether correlations between a ... More
Double charge-exchange phonon statesJul 15 2019We study double charge-exchange phonon states in neutron-rich nuclei, in particular the double isobaric analog states and the double Gamow-Teller excitations, induced by the double isospin operator $\sum_{i,j=1}^At_-(i) t_-(j)$ and spin-isospin operator ... More
Skyrme functional with tensor terms from ab initio calculationsOct 23 2018A new Skyrme functional devised to account well for standard nuclear properties as well as for spin and spin-isospin properties is presented. The main novelty of this work relies on the introduction of tensor terms guided by ab initio relativistic Brueckner-Hartree-Fock ... More
Regularization of zero-range effective interactions in finite nucleiOct 06 2014The problem of the divergences which arise in beyond mean-field calculations, when a zero-range effective interaction is employed, has not been much considered so far. Some of us have proposed, quite recently, a scheme to regularize a zero-range Skyrme-type ... More
Skyrme functional with tensor terms from \textit{ab initio} calculations of neutron-proton dropsOct 23 2018Mar 21 2019A new Skyrme functional devised to account well for standard nuclear properties as well as for spin and spin-isospin properties is presented. The main novelty of this work relies on the introduction of tensor terms guided by \textit{ab initio} relativistic ... More
Garvey-Kelson Relations for Nuclear Charge RadiiDec 02 2009The Garvey-Kelson relations (GKRs) are algebraic expressions originally developed to predict nuclear masses. In this letter we show that the GKRs provide a fruitful framework for the prediction of other physical observables that also display a slowly-varying ... More
Second-order equation of state with the full Skyrme interaction: toward new effective interactions for beyond mean-field modelsApr 06 2012In a quantum Fermi system the energy per particle calculated at the second order beyond the mean-field approximation diverges if a zero-range interaction is employed. We have previously analyzed this problem in symmetric nuclear matter by using a simplified ... More
Coulomb exchange functional with generalized gradient approximation for self-consistent Skyrme Hartree-Fock calculationsOct 05 2018Feb 14 2019We perform the self-consistent Skyrme Hartree-Fock calculation with the Coulomb exchange functional in the form of generalized gradient approximation (GGA). It is found that the Perdew-Burke-Ernzerhof GGA (PBE-GGA) Coulomb exchange functional is able ... More
Periodic orbits in the hyperchaotic Chen systemDec 15 2014In this work, we show that a zero--Hopf bifurcation take place in the Hyperchaotic Chen system as parameters vary. Using averaging theory, we prove the existence of two periodic orbits bifurcating from the zero--Hopf equilibria located at the origin of ... More
Localized form of Fock terms in nuclear covariant density functional theoryJul 26 2012In most of the successful versions of covariant density functional theory in nuclei, the Fock terms are not included explicitly, which leads to local functionals and forms the basis of their widespread applicability at present. However, it has serious ... More
Isospin violation in J/Psi to phi pi0 eta decay and the f0-a0 mixingOct 17 2012The isospin violating $J/\Psi\to \phi \pi^0 \eta$ decay is thought to be dominated by the mixing of the $f_0(980)$ and $a_0(980)$ scalar resonances. We make a theoretical evaluation of the $J/\Psi\to \phi \pi^0 \eta$ decay extending our own previous model ... More
Pseudotensor mesons as three-body resonancesJul 27 2011We show that the lightest pseudotensor mesons J^{PC}=2^-+ can be regarded as molecules made of a pseudoscalar (P) 0^-+ and a tensor 2^++ meson, where the latter is itself made of two vector (V) mesons. The idea stems from the fact that the vector-vector ... More
Nuclear Equation of State from ground and collective excited state properties of nucleiApr 17 2018This contribution reviews the present status on the available constraints to the nuclear equation of state (EoS) around saturation density from nuclear structure calculations on ground and collective excited state properties of atomic nuclei. It concentrates ... More
Covariance analysis of finite temperature density functional theory: symmetric nuclear matterJul 15 2014Aug 21 2014We study symmetric nuclear matter at finite temperature, with particular emphasis on the liquid-gas phase transition. We use a standard covariance analysis to propagate statistical uncertainties from the density functional to the thermodynamic properties. ... More
New Skyrme energy density functional for a better description of the Gamow-Teller ResonanceDec 03 2012We present a new Skyrme energy density functional (EDF) named SAMi [Phys. Rev. C 86 031306(R)]. This interaction has been accurately calibrated to reproduce properties of doubly-magic nuclei and infinite nuclear matter. The novelties introduced in the ... More
Covariance analysis for Energy Density Functionals and instabilitiesJun 07 2014Oct 06 2014We present the covariance analysis of two successful nuclear energy density functionals, (i) a non-relativistic Skyrme functional built from a zero-range effective interaction, and (ii) a relativistic nuclear energy density functional based on density ... More
A new Skyrme interaction with improved spin-isospin propertiesMay 17 2012Sep 21 2012A correct determination of the spin-isospin properties of the nuclear effective interaction should lead, among other improvements, to an accurate description of the Gamow-Teller Resonance (GTR). These nuclear excitations impact on a variety of physical ... More
Scattering of unstable particles in a finite volume: the case of pi rho scattering and the a1(1260) resonanceJan 02 2012We present a way to evaluate the scattering of unstable particles quantized in a finite volume with the aim of extracting physical observables for infinite volume from lattice data. We illustrate the method with the $\pi\rho$ scattering which generates ... More
Lambda(1405) poles obtained from pi0-Sigma0 photoproduction dataJan 24 2013Feb 01 2013We present a strategy to extract the position of the two $\Lambda(1405)$ poles from experimental photoproduction data measured recently at different energies in the $\gamma p \to K^+ \pi^0 \Sigma^0 $ reaction at Jefferson Lab. By means of a chiral dynamics ... More
The $(π^-,γγ)$ reaction in nuclei and the $σ$ meson in the mediumJan 16 2003A theoretical analysis of the $(\pi^-,\gamma\gamma)$ reaction in nuclei is made in order to find the viability of this reaction to test modifications of the $\sigma$ meson mass in nuclear matter. The $\pi\pi$ correlation in the scalar-isoscalar channel ... More
Two photons into π^0π^0Apr 02 2008We perform a theoretical study based on dispersion relations of the reaction \gamma\gamma\to \pi^0\pi^0 emphasizing the low energy region. We discuss how the f_0(980) signal emerges in \gamma\gamma\to \pi\pi within the dispersive approach and how this ... More
Influence of the nuclear symmetry energy on the structure and composition of the outer crustSep 14 2011We review and extend with nonrelativistic nuclear mean field calculations a previous study of the impact of the nuclear symmetry energy on the structure and composition of the outer crust of nonaccreting neutron stars. First, we develop a simple "toy ... More
Electron scattering in isotonic chains as a probe of the proton shell structure of unstable nucleiJul 06 2012Jan 08 2013Electron scattering on unstable nuclei is planned in future facilities of the GSI and RIKEN upgrades. Motivated by this fact, we study theoretical predictions for elastic electron scattering in the N=82, N=50, and N=14 isotonic chains from very proton-deficient ... More
Density dependence of the symmetry energy from neutron skin thickness in finite nucleiAug 05 2013The density dependence of the symmetry energy around saturation density, characterized by the slope parameter L, is studied using information provided by the neutron skin thickness in finite nuclei. An estimate for L is obtained from experimental data ... More
Constraints on the Neutron Skin and the Symmetry Energy from the Anti-analog Giant Dipole Resonance in 208PbApr 27 2015We investigate the impact of the neutron-skin thickness Delta(R) on the energy difference between the anti-analog giant dipole resonance (AGDR), E(AGDR), and the isobaric analog state (IAS), E(IAS), in a heavy nucleus such as 208Pb. For guidance, we first ... More
Non-Perturbative Study of the Light Pseudoscalar Masses in Chiral DynamicsAug 28 2006Dec 02 2007We perform a non-perturbative chiral study of the masses of the lightest pseudoscalar mesons. In the calculation of the self-energies we employ the S-wave meson-meson amplitudes taken from Unitary Chiral Perturbation Theory (UCHPT) that include the lightest ... More
Study of the neutron skin thickness of ${}^{208}$Pb in mean field modelsJun 26 2011We study whether the neutron skin thickness $\Delta r_{np}$ of ${}^{208}$Pb originates from the bulk or from the surface of the neutron and proton density distributions in mean field models. We find that the size of the bulk contribution to $\Delta r_{np}$ ... More
Nuclear symmetry energy probed by neutron skin thickness of nucleiJun 17 2008Feb 20 2009We describe a relation between the symmetry energy coefficients c_sym(rho) of nuclear matter and a_sym(A) of finite nuclei that accommodates other correlations of nuclear properties with the low-density behavior of c_sym(rho). Here we take advantage of ... More
Influence of the single-particle structure on the nuclear surface and the neutron skinApr 03 2014Jun 05 2014We analyze the influence of the single-particle structure on the neutron density distribution and the neutron skin in Ca, Ni, Zr, Sn, and Pb isotopes. The nucleon density distributions are calculated in the Hartree-Fock+BCS approach with the SLy4 Skyrme ... More
Origin of the neutron skin thickness of 208Pb in nuclear mean-field modelsOct 26 2010Dec 07 2010We study whether the neutron skin thickness (NST) of 208Pb originates from the bulk or from the surface of the nucleon density distributions, according to the mean-field models of nuclear structure, and find that it depends on the stiffness of the nuclear ... More
Analysis of bulk and surface contributions in the neutron skin of nucleiMar 26 2010May 19 2010The neutron skin thickness of nuclei is a sensitive probe of the nuclear symmetry energy having multiple implications for nuclear and astrophysical studies. However, precision measurements of this observable are difficult. The analysis of the experimental ... More
Outer crust of a cold non-accreting magnetarMay 27 2015Sep 11 2015The outer crust structure and composition of a cold, non-accreting magnetar is studied. We model the outer crust to be made of fully equilibrated matter where ionized nuclei form a Coulomb crystal embedded in an electron gas. The main effects of the strong ... More
Nuclear symmetry energy and neutron skin thicknessFeb 21 2012The relation between the slope of the nuclear symmetry energy at saturation density and the neutron skin thickness is investigated. Constraints on the slope of the symmetry energy are deduced from the neutron skin data obtained in experiments with antiprotonic ... More
Neutron skin of 208Pb, nuclear symmetry energy, and the parity radius experimentMar 09 2011Jun 17 2011A precise determination of the neutron skin thickness of a heavy nucleus sets a basic constraint on the nuclear symmetry energy (the neutron skin thickness is the difference of the neutron and proton rms radii of the nucleus). The parity radius experiment ... More
The Smoothness of Physical ObservablesMay 13 2009May 15 2009The Garvey-Kelson (GK) relations are powerful algebraic expressions connecting the masses of neighboring atomic nuclei and derived under reasonable physical assumptions. In this contribution we show that these relations are even more general than originally ... More
Theoretical study of elastic electron scattering off stable and exotic nucleiAug 08 2008Oct 02 2008Results for elastic electron scattering by nuclei, calculated with charge densities of Skyrme forces and covariant effective Lagrangians that accurately describe nuclear ground states, are compared against experiment in stable isotopes. Dirac partial-wave ... More
Neutron skin thickness in droplet model with surface width dependence: indications of softness of the nuclear symmetry energyJun 04 2009Jul 30 2009We analyze the neutron skin thickness in finite nuclei with the droplet model and effective nuclear interactions. The ratio of the bulk symmetry energy J to the so-called surface stiffness coefficient Q has in the droplet model a prominent role in driving ... More
Anomalous diffusion in silo drainageJul 14 2006May 25 2007The silo discharge process is studied by molecular dynamics simulations. The development of the velocity profile and the probability density function for the displacements in the horizontal and vertical axis are obtained. The PDFs obtained at the beginning ... More
Scalar radius of the pion and zeros in the form factorMar 31 2007Apr 25 2007The quadratic pion scalar radius, \la r^2\ra^\pi_s, plays an important role for present precise determinations of \pi\pi scattering. Recently, Yndur\'ain, using an Omn\`es representation of the null isospin(I) non-strange pion scalar form factor, obtains ... More
Identification of arches in 2D granular packingsMar 29 2006Jul 14 2006We identify arches in a bed of granular disks generated by a molecular dynamic-type simulation. We use the history of the deposition of the particles to identify the supporting contacts of each particle. Then, arches are defined as sets of mutually stable ... More
Generalized Stieltjes and other integral operators on Sobolev-Lebesgue spacesJun 25 2019For $\mu>\beta>0$, the generalized Stieltjes operators $$ \mathcal{S}_{\beta,\mu} f(t):={t^{\mu-\beta}}\int_0^\infty {s^{\beta-1}\over (s+t)^{\mu}}f(s)ds, \qquad t>0, $$ defined on Sobolev spaces $\mathcal{T}_p^{(\alpha)}(t^\alpha)$ (where $\alpha\ge ... More
Computations modulo regular chainsMar 21 2009Jul 25 2009The computation of triangular decompositions are based on two fundamental operations: polynomial GCDs modulo regular chains and regularity test modulo saturated ideals. We propose new algorithms for these core operations relying on modular methods and ... More
Quantum loops in radiative decays of the $a_1$ and $b_1$ axial-vector mesonsNov 07 2006Sep 25 2007A previous model where the low-lying axial-vector mesons are dynamically generated, implementing unitarity in coupled channels in the vector-pseudoscalar ($VP$) meson interaction, is applied to evaluate the decay widths of the a_1(1260)$ and $b_1(1235)$ ... More
$η\to π^0 γγ$ decay within unitarized chiral perturbation theoryOct 21 2002May 02 2003We improve the calculations of the $\eta \to \pi^0 \gamma \gamma$ decay within the context of meson chiral lagrangians. We use a chiral unitary approach for the meson-meson interaction, thus generating the $a_0(980)$ resonance and fixing the longstanding ... More
On the nature of the K*2(1430), K*3(1780), K*4(2045), K*5(2380) and K*6 as K*--multi-rho statesOct 04 2010We show that the $K^*_2(1430)$, $K^*_3(1780)$, $K^*_4(2045)$, $K^*_5(2380)$ and a not yet discovered $K_6^*$ resonance are basically molecules made of an increasing number of $\rho(770)$ and one $K^*(892)$ mesons. The idea relies on the fact that the ... More
On the nature of the $Λ(1405)$ and $Λ(1670)$ from their $N_c$ behavior in chiral dynamicsApr 08 2008We study the behavior with the number of colors ($N_c$) of the $\Lambda(1405)$ and $\Lambda(1670)$ resonances obtained dynamically within the chiral unitary approach. The leading order meson-baryon interaction, used as the kernel of the unitarization ... More
The composite nature of the $Λ(1520)$ resonanceApr 24 2014Sep 16 2014Recently, the Weinberg compositeness condition of a bound state was generalized to account for resonant states and higher partial waves. We apply this extension to the case of the $\Lambda(1520)$ resonance and quantify the weight of the meson-baryon components ... More
Discussion of the eta to pi^0 gamma gamma decay within a chiral unitary approachNov 02 2005We improve the calculations of the $\eta \to \pi^0 \gamma \gamma$ decay within the context of meson chiral lagrangians. We use a chiral unitary approach for the meson-meson interaction, thus generating the $a_0(980)$ resonance and fixing the longstanding ... More
Measuring the $φ$ meson width in the medium from $p$ induced $φ$ production in nucleiDec 17 2004We study the $A$ dependence of the $\phi$ meson production cross section in proton nucleus reactios at energies just above threshold, which are accessible in an experimental facility like COSY. This $A$ dependence has two sources: the distortion of the ... More
The $φ$ meson width in the medium from proton induced $φ$ production in nucleiMar 22 2004Apr 15 2005We perform calculations for the production of $\phi$ mesons in nuclei at energies just above threshold and study the $A$ dependence of the cross section. We use results for the $\phi$ selfenergy in the medium obtained within a chiral unitary approach. ... More
The LHCb pentaquark as a $\bar{D}^*Σ_c-\bar{D}^*Σ_c^*$ molecular stateJul 15 2015Oct 21 2015We perform a theoretical analysis of the $\Lambda_b \to J/\psi K^- p$ reaction from where a recent LHCb experiment extracts a $\Lambda(1405)$ contribution in the $K^- p$ spectrum close to threshold and two baryon states of hidden charm in the $J/\psi\,p$ ... More
The MarkI helioseismic experiment.I. Measurements of the solar gravitational redshift (1976-2013)Jun 23 2014The resonant scattering solar spectrophotometer 'Mark-I', designed and build at the University of Birmingham (UK) and located at the Observatorio del Teide (Spain), has been continuously in operation for the past 38 years. During this period of time, ... More
Improved dispersion relations for γγ\to π^0π^0Aug 13 2007Nov 06 2007We perform a dispersive theoretical study of the reaction \gamma\gamma\to pi^0\pi^0 emphasizing the low energy region. The large source of theoretical uncertainty to calculate the \gamma\gamma\to\pi^0\pi^0 total cross section for \sqrt{s}\gtrsim 0.5 GeV ... More
Meson loops in the $f_0(980)$ and $a_0(980)$ radiative decays into $ρ$, $ω$Feb 04 2008We calculate the radiative decay widths of the $a_0(980)$ and $f_0(980)$ scalar mesons into $\rho\gamma$ and $\omega\gamma$ considering the dynamically generated nature of these scalar resonances within the realm of the Chiral Unitary Approach. The main ... More
Radiative decay into $γP$ of the low lying axial-vector mesonsMar 06 2008We evaluate the radiative decay into a pseudoscalar meson and a photon of the whole set of the axial-vector mesons dynamically generated from the vector-pseudoscalar meson ($VP$) interaction. We take into account tree level and loop diagrams coming from ... More
Decay of axial-vector mesons into VP and P$γ$Jun 20 2003Aug 26 2004We propose a phenomenological Lagrangian for the decay of the SU(3) nonets of the axial-vector mesons of $J^{PC}=1^{+-},1^{++}$ into a vector meson and a pseudoscalar constructed with tensor fields for the vector and axial-vector mesons. The formulation ... More
Issues in Electric-Magnetic DualitySep 20 2002Chapters : 1. Introduction to electric-magnetic duality 2. Classical duality in bosonic brane electrodynamics 3. Massless spin two gauge theory 4. Duality-symmetric actions and chiral forms 5. BRST quantization of duality-symmetric Maxwell's theory 6. ... More
A matrix phase for the phi^4 scalar field on the fuzzy sphereFeb 27 2004May 13 2004The critical properties of the real phi^4 scalar field theory are studied numerically on the fuzzy sphere. The fuzzy sphere is a matrix (non commutative) discretisation of the algebra of functions on the usual two dimensional sphere. It is also one of ... More
Diffractive Rho Meson Electroproduction at High Q^2 and High |t|Jul 02 2002The electroproduction of rho mesons is studied at HERA with the H1 detector at high Q^2 and high |t|. Cross sections are measured as a function of Q^2, W and t. The W dependence of the gamma*-p cross section is observed to increase with Q^2 from values ... More
The mutual singularity of harmonic measure and Hausdorff measure of codimension smaller than oneJan 23 2019Jan 26 2019Let $\Omega\subset\mathbb R^{n+1}$ be open and let $E\subset \partial\Omega$ with $0<H^s(E)<\infty$, for some $s\in(n,n+1)$, satisfy a local capacity density condition. In this paper it is shown that the harmonic measure cannot be mutually absolutely ... More
Measuring precise radial velocities on individual spectral lines. I. Validation of the method and application to mitigate stellar activitySep 05 2018Oct 22 2018Stellar activity is the main limitation to the detection of Earth-twins using the RV technique. Despite many efforts in trying to mitigate the effect of stellar activity using empirical and statistical techniques, it seems that we are facing an obstacle ... More
Boundedness of stable solutions to semilinear elliptic equations: a surveyApr 20 2017This article is a survey on boundedness results for stable solutions to semilinear elliptic problems. For these solutions, we present the currently known $L^{\infty}$ estimates that hold for all nonlinearities. Such estimates are known to hold up to dimension ... More
What determines the ultimate precision of a quantum computer?Feb 24 2017Apr 12 2019A quantum error correction (QEC) code uses $N_{\rm c}$ quantum bits to construct one "logical" quantum bits of better quality than the original "physical" ones. QEC theory predicts that the failure probability $p_L$ of logical qubits decreases exponentially ... More
Barycentric Subspace Analysis on ManifoldsJul 11 2016Oct 04 2017This paper investigates the generalization of Principal Component Analysis (PCA) to Riemannian manifolds. We first propose a new and general type of family of subspaces in manifolds that we call barycentric subspaces. They are implicitly defined as the ... More
Phragmén's sequential method with a variance criterionNov 18 2016A variant of Phragm\'en's method for proportional representation via approval voting is briefly explored. Instead of D'Hondt's rule, this variant generalizes Sainte-Lagu\"e's rule.
A conjecture for q-decomposition matrices of cyclotomic v-Schur algebrasMay 18 2005Apr 27 2006The Jantzen sum formula for cyclotomic v-Schur algebras yields an identity for some q-analogues of the decomposition matrices of these algebras. We prove a similar identity for matrices of canonical bases of higher-level Fock spaces. We conjecture then ... More
Calibrations and null-Lagrangians for nonlocal perimeters and an application to the viscosity theoryMay 26 2019For nonnegative even kernels $K$, we consider the $K$-nonlocal perimeter functional acting on sets. Assuming the existence of a foliation of space made of solutions of the associated $K$-nonlocal mean curvature equation in an open set $\Omega\subset\mathbb{R}^n$, ... More
Expected number of critical points of random holomorphic sections over complex projective spaceJan 24 2017Jan 25 2017We study the high dimensional asymptotics of the expected number of critical points of a given Morse index of Gaussian random holomorphic sections over complex projective space. We explicitly compute the exponential growth rate of the expected number ... More
Well-posedness for a higher order nonlinear Schrodinger equation in Sobolev spaces of negative indicesJul 31 2003We prove that, the initial value problem associated to u_{t} + i\alphau_{xx} + \beta u_{xxx} + i\gamma |u|^{2}u = 0, x,t \in R, is locally well-posed in Sobolev spaces H^{s} for s>-1/4.
On Searches for Gravitational Dark Matter with Quantum SensorsJul 12 2019The possibility of searching for dark matter with quantum sensors has recently received a lot of attention. In this short paper, we discuss the possibility of searching for gravitational dark matter with quantum sensors and identify a very narrow window ... More
The Fano surface of the Klein cubic threefoldJan 27 2010We prove that the Klein cubic threefold $F$ is the only smooth cubic threefold which has an automorphism of order 11. We compute the period lattice of the intermediate Jacobian of $F$ and study its Fano surface $S$. We compute also the set of fibrations ... More
Elliptic curve configurations on Fano surfacesApr 11 2008Jan 27 2010The elliptic curves on a surface of general type constitute an obstruction for the cotangent sheaf to be ample. In this paper, we give the classification of the configurations of the elliptic curves on the Fano surface of a smooth cubic threefold. That ... More
Characterization of $n$-rectifiability in terms of Jones' square function: Part IJan 07 2015Nov 12 2017In this paper it is shown that if $\mu$ is a finite Radon measure in $\mathbb R^d$ which is $n$-rectifiable and $1\leq p\leq 2$, then $$\int_0^\infty \beta_{\mu,p}^n(x,r)^2\,\frac{dr}r<\infty \quad {for $\mu$-a.e. $x\in\mathbb R^d$,}$$ where $$\beta_{\mu,p}^n(x,r) ... More
Variance optimal hedging with application to Electricity marketsNov 10 2017Aug 28 2018In Electricity markets, illiquidity, transaction costs and market price characteristics prevent managers to replicate exactly contracts. A residual risk is always present and the hedging strategy depends on a risk criterion chosen. We present an algorithm ... More
Influence of the symmetry energy on the giant monopole resonance of neutron-rich nucleiJun 16 2009Apr 06 2010We analyze the influence of the density dependence of the symmetry energy on the average excitation energy of the isoscalar giant monopole resonance (GMR) in stable and exotic neutron-rich nuclei by applying the relativistic extended Thomas-Fermi method ... More
Interplay between low-lying isoscalar and isovector dipole modes: a comparative analysis between semi-classical and quantum approachesJul 26 2018Feb 22 2019We perform Time Dependent Hartree-Fock (TDHF) calculations to investigate the small amplitude dipole response of selected neutron-rich nuclei and Sn isotopes. A detailed comparison with the dipole strength predicted by Random-Phase Approximation (RPA) ... More
Towards a self-consistent dynamical nuclear modelJan 04 2017Density Functional Theory (DFT) is a powerful and accurate tool exploited in Nuclear Physics to investigate the ground-state and some collective properties of nuclei along the whole nuclear chart. Models based on DFT are, however, not suitable for the ... More
Relativistic mean field interaction with density dependent meson-nucleon vertices based on microscopical calculationsOct 11 2011Jun 08 2016Although ab-initio calculations of relativistic Brueckner theory lead to large scalar isovector fields in nuclear matter, at present, successful versions of covariant density functional theory neglect the interactions in this channel. A new high precision ... More
Second--order equation of state with the Skyrme interaction. Cutoff and dimensional regularization with the inclusion of rearrangement termsApr 21 2016We evaluate the second--order (beyond--mean--field) contribution to the equation of state of nuclear matter with the effective Skyrme force and use cutoff and dimensional regularizations to treat the ultraviolet divergence produced by the zero--range ... More
Local covariant density functional constrained by the relativistic Hartree-Fock theoryOct 29 2012The recent progress in the localized covariant density functional constrained by the relativistic Hartree-Fock theory is briefly presented by taking the Gamow-Teller resonance in 90Zr as an example. It is shown that the constraints introduced by the Fock ... More
Higher spin algebras as higher symmetriesApr 06 2007Aug 23 2007The exhaustive study of the rigid symmetries of arbitrary free field theories is motivated, along several lines, as a preliminary step in the completion of the higher-spin interaction problem in full generality. Some results for the simplest example (a ... More
Clusters, Graphs, and Networks for Analysing Internet-Web-Supported Communication within a Virtual CommunityJul 10 2007The proposal is to use clusters, graphs and networks as models in order to analyse the Web structure. Clusters, graphs and networks provide knowledge representation and organization. Clusters were generated by co-site analysis. The sample is a set of ... More
Hadronic B Decays to Charm and Charmonium With the BaBar ExperimentSep 17 2008Oct 17 2008The {\it BaBar} experiment has recorded the decays of more than 465$\times 10^6 B\bar{B}$ pairs since 1999, and is reaching an unprecedented precision in the measurement of hadronic B decays. The following results are presented: tests of QCD factorization ... More
Renormalized stress tensor in one-bubble spacetimesApr 08 1999We compute the two-point function and the renormalized expectation value of the stress tensor of a quantum field interacting with a nucleating bubble. Two simple models are considered. One is the massless field in the Vilenkin-Ipser-Sikivie spacetime ... More
Cosmological Evolution of the Higgs Boson's Vacuum Expectation ValueJul 21 2017We point out that the expansion of the universe leads to a cosmological time evolution of the vacuum expectation of the Higgs boson. Within the standard model of particle physics, the cosmological time evolution of the vacuum expectation of the Higgs ... More
Computations with p-adic numbersJan 24 2017This document contains the notes of a lecture I gave at the "Journ\'ees Nationales du Calcul Formel" (JNCF) on January 2017. The aim of the lecture was to discuss low-level algorithmics for p-adic numbers. It is divided into two main parts: first, we ... More
The Dual Standard Model and the 750 GeV Events at the LHCApr 21 2016The aim of this short paper is to discuss the recently observed excess at 750 GeV by both CMS and ATLAS in the light of the dual standard model. Within this framework it is natural to introduce neutral spin 0 and/or spin 2 $SU(2)$ glue mesons which could ... More
On the bit-size of non-radical triangular setsOct 17 2017We present upper bounds on the bit-size of coefficients of non-radical lexicographical Groebner bases in purely triangular form (triangular sets) of dimension zero. This extends a previous work [Dahan-Schost, Issac'2004], constrained to radical triangular ... More
Rigid covariance, equivalence principle and Fermi rigid coordinates:gravitational wavesJul 17 2018Jan 21 2019For a given space-time and for an arbitrary time-like geodesic, we analyze the conditions for the construction of Fermi coordinates so that they are also rigid covariant. We then apply these conditions to linear plane gravitational waves.
Improved Low-qubit Hidden Shift AlgorithmsJan 31 2019Hidden shift problems are relevant to assess the quantum security of various cryptographic constructs. Multiple quantum subexponential time algorithms have been proposed. In this paper, we propose some improvements on a polynomial quantum memory algorithm ... More
A proof of the weak (1,1) inequality for singular integrals with non doubling measures based on a Calderon-Zygmund decompositionFeb 25 2000Given a doubling measure $\mu$ on $R^d$, it is a classical result of harmonic analysis that Calderon-Zygmund operators which are bounded in $L^2(\mu)$ are also of weak type (1,1). Recently it has been shown that the same result holds if one substitutes ... More
On concrete models for local operator spacesOct 28 2008In this short note, we propose a concrete analogue of the space $\cL(H)$ for local operator spaces, the multinormed $C^*$-algebra $\displaystyle\prod_{\alpha} \cL(H_{\alpha})$.
Painleve's problem and the semiadditivity of analytic capacityApr 02 2002Let $\gamma(E)$ be the analytic capacity of a compact set $E$ and let $\gamma_+(E)$ be the capacity of $E$ originated by Cauchy transforms of positive measures. In this paper we prove that $\gamma(E)\approx\gamma_+(E)$ with estimates independent of $E$. ... More
Principal values for Riesz transforms and rectifiabilityAug 01 2007Let $E\subset R^d$ with $H^n(E)<\infty$, where H^n stands for the $n$-dimensional Hausdorff measure. In this paper we prove that E is n-rectifiable if and only if the limit $$\lim_{\ve\to0}\int_{y\in E:|x-y|>\ve} \frac{x-y}{|x-y|^{n+1}} dH^n(y)$$ exists ... More
Requirements Management for Service Providers: the Case of Services for CitizensJan 19 2013Take the Internet of Things, a piece of cloud computing, a handful of smart cities, don't forget social platforms, flavour it with mobile technologies and ever-changing environments, shake it up and... voila! What a wonderful service! Oops! Wait a minute, ... More
The Asset Liability Management problem of a nuclear operator : a numerical stochastic optimization approachNov 15 2016We numerically study an Asset Liability Management problem linked to the decommissioning of French nuclear power plants. We link the risk aversion of practitioners to an optimization problem. Using different price models we show that the optimal solution ... More
A priori estimates for solutions of a nonlinear dispersive equationAug 24 2005Mar 19 2010This paper has been withdrawn by the author due to a crucial error.
Sharp global well-posedness for a higher order Schrödinger equationApr 28 2005Apr 30 2005Using the theory of almost conserved energies and the ``I-method'' developed by Colliander, Keel, Staffilani, Takaoka and Tao, we prove that the initial value problem for a higher order Schr\"odinger equation is globally well-posed in Sobolev spaces of ... More
Representations semi-stables de torsion dans le cas peu ramifieJul 17 2004Oct 24 2004Let K be a local field of mixed characteristic not absolutely ramified. Fontaine-Laffaille theory gives a description of the torsion crystalline Z_p-representations of the absolute Galois group of K (p denotes the characteristic of the residual field). ... More