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Results for "E. I. Paredes Aulestia"

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Extremely large magnetoresistance and the complete determination of the Fermi surface topology in the semimetal ScSbJun 21 2018Aug 07 2018We report the magnetoresistance of ScSb, which is a semimetal with a simple rocksalt-type structure. We found that the magnetoresistance reaches $\sim$28000 % at 2 K and 14 T in our best sample, and it exhibits a resistivity plateau at low temperatures. ... More
Nonsaturating large magnetoresistance in the high carrier density nonsymmorphic metal CrPMar 14 2019The band structure of high carrier density metal CrP features an interesting crossing at the Y point of the Brillouin zone. The crossing, which is protected by the nonsymmorphic symmetry of the space group, results in a hybrid, semi-Dirac-like energy-momentum ... More
Pressure-induced enhancement of non-polar to polar transition temperature in metallic LiOsO$_3$Jun 02 2018Jun 06 2018LiOsO$_3$ undergoes a continuous transition from a centrosymmetric $R\bar{3}c$ structure to a polar $R3c$ structure at $T_s=140$~K. By combining transport measurements and first-principles calculations, we find that $T_s$ is enhanced by applied pressure, ... More
From Cooper pairs to Luttinger liquids with bosonic atoms in optical latticesJul 01 2002We propose a scheme to observe typical strongly correlated fermionic phenomena with bosonic atoms in optical lattices. For different values of the sign and strength of the scattering lengths it is possible to reach a "superconducting" regime, where the ... More
Simple model for reverse buoyancy in a vibrated granular systemNov 06 2002Large objects, immersed in a homogeneous granular system, migrate when subjected to vibrations. Under certain conditions large heavy objects rise and similar light ones sink to the bottom. This is called reverse buoyancy. We report an experimental study ... More
Quantifying star formation activity in the inner 1kpc of local MIR bright QSOsJan 08 2019We examine star formation activity in a distance- (z<0.1) and flux-limited sample of quasars (QSOs). Mid-infrared (MIR) spectral diagnostics at high spatial resolution (~0.4 arcsec) yield star formation rates (SFRs) in the inner regions (~300 pc to 1 ... More
Pfaffian-like ground state for 3-body-hard-core bosons in 1D latticesAug 01 2006We propose a Pfaffian-like Ansatz for the ground state of bosons subject to 3-body infinite repulsive interactions in a 1D lattice. Our Ansatz consists of the symmetrization over all possible ways of distributing the particles in two identical Tonks-Girardeau ... More
Fermionizing a small gas of ultracold bosonsMar 04 2002We study the physics of a rapidly-rotating gas of ultracold atomic bosons, with an internal degree of freedom. We show that in the limit of rapid rotation of the trap the problem exactly maps onto that of non-interacting fermions with spin in the lowest ... More
Exploiting Quantum Parallelism To Simulate Quantum Random Many-Body SystemsMay 11 2005We present an algorithm that exploits quantum parallelism to simulate randomness in a quantum system. In our scheme, all possible realizations of the random parameters are encoded quantum mechanically in a superposition state of an auxiliary system. We ... More
Adiabatic Path to Fractional Quantum Hall States of a Few Bosonic AtomsMay 10 2004We propose a realistic scheme to create motional entangled states of a few bosonic atoms. It can experimentally be realized with a gas of ultra cold bosonic atoms trapped in a deep optical lattice potential. By simultaneously deforming and rotating the ... More
Fermionic Atoms in Optical SuperlatticesJun 19 2003Fermionic atoms in an optical superlattice can realize a very peculiar Anderson lattice model in which impurities interact with each other through a discretized set of delocalized levels. We investigate the interplay between Kondo effect and magnetism ... More
Exploring the connection between the stellar wind and the non-thermal emission in LS 5039Mar 19 2007Jul 18 2007LS 5039 has been observed with several X-ray instruments so far. The source presents X-ray variability at orbital timescales in flux and photon index. The system harbors an O-type main sequence star with moderate mass loss. At present, the link between ... More
On the formation and evolution of the first Be star in a black hole binary MWC 656Apr 13 2015Jun 11 2015We find that the formation of MWC 656 (the first Be binary containing a black hole) involves a common envelope phase and a supernova explosion. This result supports the idea that a rapidly rotating Be star can emerge out of a common envelope phase, which ... More
Spectral energy distribution of the gamma-ray microquasar LS 5039Sep 05 2005Jan 05 2006The microquasar LS 5039 has recently been detected as a source of very high energy (VHE) $\gamma$-rays. This detection, that confirms the previously proposed association of LS 5039 with the EGRET source 3EG~J1824$-$1514, makes of LS 5039 a special system ... More
The Lifetimes of Molecular Cloud Cores: What is the Role of the Magnetic Field?Mar 04 2004We discuss the lifetimes and evolution of dense cores formed as turbulent density fluctuations in magnetized, isothermal molecular clouds. We consider numerical simulations in which we measure the cores' magnetic criticality and Jeans stability in relation ... More
Topological phase transitions in liquid crystals -- Transiciones de fase topológicas en cistales l{'ı}quidosJan 23 2004By means of Monte Carlo simulations, using finite size scaling and conformal transformations, evidences of a topological phase transition in liquid crystals in two dimensions are reported. A paramagnetic phase appears at high temperature whereas a quasi-long-range-order ... More
Evidence for a topological transition in nematic-to-isotropic phase transition in two dimensionsJan 07 2003Feb 03 2003The nematic-to-isotropic orientational phase transition, or equivalently the $RP^2$ model, is considered in two dimensions and the question of the nature of the phase transition is addressed. Using powerful conformal techniques adapted to the investigation ... More
Influence of quenched dilution on the quasi-long-range ordered phase of the 2d XY modelSep 22 2003The influence of non magnetic impurities in the 2d XY model is investigated through Monte Carlo (MC) simulations. The general picture of the transition is fully understood from the Harris criterion which predicts that the universality class is unchanged, ... More
High-mass microquasars and low-latitude gamma-ray sourcesMay 03 2004Sep 09 2004Population studies of unidentified EGRET sources suggest that there exist at least three different populations of galactic gamma-ray sources. One of these populations is formed by young objects distributed along the galactic plane with a strong concentration ... More
1/2-Anyons in small atomic Bose-Einstein condensatesMar 12 2001We discuss a way of creating, manipulating and detecting anyons in rotating Bose-Einstein condensates consisting of a small number of atoms . By achieving a quasidegeneracy in the atomic motional states we drive the system into a 1/2--Laughlin state for ... More
Simulation of grains in a vibrated U-tube without interstitial fluidJun 28 2012We present a computational study using Molecular Dynamics of the development of an accumulation of grains in one side of a two dimensional U-tube under vertical vibrations. Studying the evolution of the height difference between the centers of mass of ... More
Leptonic emission from microquasar jets: from radio to very high-energy gamma-raysMay 18 2006Microquasars are sources of very high-energy gamma-rays and, very probably, high-energy gamma-ray emitters. We propose a model for a jet that can allow to give accurate observational predictions for jet emission at different energies and provide with ... More
A broadband leptonic model for gamma-ray emitting microquasarsSep 05 2005Nov 30 2005Observational and theoretical studies point to microquasars (MQs) as possible counterparts of a significant fraction of the unidentified gamma-ray sources detected so far. At present, a proper scenario to explain the emission beyond soft X-rays from these ... More
Spin Effect on the Resonant Tunneling Characteristics of a Double-Barrier Heterostructures Under Longitudinal StressesJun 01 2007Theoretical research on electronic properties in mesoscopic condensed matter systems has focused primarily on the electron charge freedom degrees, while its corresponding spin freedom degrees have not yet received the same attention. Nevertheless nowadays ... More
A Search for Larson-Type Relations in Numerical Simulations of the ISM. Evidence for Non-Constant Column DensitiesAug 01 1996We present results from a statistical study of clouds in two-dimensional numerical simulations of the interstellar medium. The clouds in the simulations exhibit a differential mass spectrum $dN(M)/dM \sim M^{-1.44 \pm 0.1}$ and a velocity dispersion-size ... More
On the Nature of the variable gamma-ray sources in the GalaxySep 09 2004Sep 05 2005Population studies of EGRET gamma-ray sources indicate that there is a distinctive population of bright sources at low galactic latitudes. The sources have a distribution consistent with that of young galactic objects, with a concentration toward the ... More
A Holistic Scenario of Turbulent Molecular Cloud Evolution and Control of the Star Formation Efficiency. First TestsJan 28 2003We compile a holistic scenario for molecular cloud (MC) evolution and control of the star formation efficiency (SFE), and present a first set of numerical tests of it. A {\it lossy} compressible cascade can generate density fluctuations and further turbulence ... More
Spectral and variability properties of LS 5039 from radio to very high-energy gamma-raysMay 19 2006Microquasars are X-ray binaries with relativistic jets. The microquasar LS 5039 turned out to be the first high-energy gamma-ray microquasar candidate due to its likely association with the EGRET source 3EG J1824-1514. Further theoretical studies supported ... More
Supersymmetry and flavor in a sugra dual of N=1 Yang-MillsDec 10 2004Jan 07 2005Some field theory aspects can be addressed holographically by introducing D-branes in the string theory duals. In this work, we study this issue in the framework of a dual of N=1 YM, the so-called Maldacena-Nunez model. Some supersymmetric embeddings ... More
Merging Quantum Loop Gases: a Route to Non-Abelian Topological PhasesSep 26 2012Condensation of quantum loops naturally leads to topological phases with Abelian excitations. Here, I propose that non-Abelian topological phases can arise from merging two (or several) identical Abelian quantum loop condensates. I define merging through ... More
On unquenched N=2 holographic flavorOct 25 2006The addition of fundamental degrees of freedom to a theory which is dual (at low energies) to N=2 SYM in 1+3 dimensions is studied. The gauge theory lives on a stack of Nc D5 branes wrapping an S^2 with the appropriate twist, while the fundamental hypermultiplets ... More
A Be-type star with a black hole companionJan 15 2014Stellar-mass black holes have all been discovered through X-ray emission, which arises from the accretion of gas from their binary companions (this gas is either stripped from low-mass stars or supplied as winds from massive ones). Binary evolution models ... More
Granular instability in a vibrated U tubeMay 19 2007We study experimentally the collective motion of grains inside a U shaped tube undergoing vertical oscillations, and we develop a very simple quantitative model that captures relevant features of the observed behaviour. The height difference between the ... More
On the binary nature of the gamma-ray sources AGL J2241+4454 (=MWC 656) and HESS J0632+057 (=MWC 148)Jan 09 2012Mar 21 2012We present optical spectroscopy of MWC 656 and MWC 148, the proposed optical counterparts of the gamma-ray sources AGL J2241+4454 and HESS J0632+0 57, respectively. The main parameters of the Halpha emission line (EW, FWHM and centroid velocity) in these ... More
Ill-distributed sets over global fields and exceptional sets in Diophantine GeometryJan 03 2019Let $K\subseteq \mathbb{R}$ be a number field. Using techniques of discrete analysis, we prove that for definable sets $X$ in $\mathbb{R}_{\exp}$ of dimension at most $2$ a conjecture of Wilkie about the density of rational points is equivalent to the ... More
EVN and MERLIN confirmation of the LS5039 jetsJul 09 2002The microquasar nature of LS5039 was revealed by May 1999 VLBA+VLA observations showing a two-sided jet at milliarcsecond scales. Here we present follow-up interferometric observations carried out with the EVN and MERLIN at 5 GHz in March 2000. The obtained ... More
The roughness of the last scattering surfaceJun 22 1999We propose an alternative analysis of the microwave background temperature anisotropy maps that is based on the study of the roughness of natural surfaces. We apply it to large angle anisotropies, such as those measured by COBE-DMR. We show that for a ... More
Microquasar models for 3EG J1828+0142 and 3EG J1735-1500Sep 09 2004Microquasars are promising candidates to emit high-energy gamma-rays. Moreover, statistical studies show that variable EGRET sources at low galactic latitudes could be associated with the inner spiral arms. The variable nature and the location in the ... More
Nonthermal processes and neutrino emission from the black hole GRO J0422+32 in a bursting stateSep 05 2012GRO J0422+32 is a member of the class of low-mass X-ray binaries (LMXBs). It was discovered during an outburst in 1992. During the entire episode a persistent power-law spectral component extending up to $\sim 1$ MeV was observed, which suggests that ... More
Observation of the Meissner effect with ultracold atoms in bosonic laddersFeb 04 2014We report on the observation of the Meissner effect in bosonic flux ladders of ultracold atoms. Using artificial gauge fields induced by laser-assisted tunneling, we realize arrays of decoupled ladder systems that are exposed to a uniform magnetic field. ... More
Exploring the high frequency emission of radio loud X-ray binariesMay 25 2000We report millimetre-wave continuum observations of the X-ray binaries Cygnus X-3, SS 433, LSI+61 303, Cygnus X-1 and GRS 1915+105. The observations were carried out with the IRAM 30 m-antenna at 250 GHz (1.25 mm) from 1998 March 14 to March 20. These ... More
Supersymmetric solutions of supergravity from wrapped branesJul 02 2004Aug 31 2004We consider several solutions of supergravity with reduced supersymmetry which are related to wrapped branes, and elaborate on their geometrical and physical interpretation. The Killing spinors are computed for each configuration. In particular, all the ... More
Looking for extended nuclear emission in a sample of nearby QSOsApr 10 2013We present MIR sub-arcsec observations of Mrk 1383, a nearby QSO, part of a sample of nearby QSOs currently being observed with the 10.4 m Gran Telescopio de Canarias (GTC). The radial profile of the QSO is analyzed and we find that most of the MIR emission ... More
Orbital Parameters of the Microquasar LSI +61 303Apr 14 2005New optical spectroscopy of the HMXB microquasar LSI +61 303 is presented. Eccentric orbital fits to our radial velocity measurements yield updated orbital parameters in good agreement with previous work. Our orbital solution indicates that the periastron ... More
Exact Parent Lattice Hamiltonian for One-Dimensional Non-Abelian Fractional Quantum Hall LiquidsNov 25 2011Nov 29 2011I present a family of one-dimensional time reversal lattice Hamiltonians whose exact ground states are bosonic non-Abelian fractional quantum Hall liquids with well defined total chiral momentum. These Hamiltonians describe k-hard-core bosons and involve ... More
Analytical and Experimental Study of Conical Telescoping Springs With Nonconstant PitchJan 15 2019Most research papers that exploit conical springs focus only on conical springs with a constant pitch. In order to increase the range of possibilities for designers, this paper proposes a study of conical springs with other types of spirals projected ... More
Optical spectroscopy of microquasar candidates at low galactic latitudesJan 23 2004We report optical spectroscopic observations of a sample of 6 low-galactic latitude microquasar candidates selected by cross-identification of X-ray and radio point source catalogs for |b|<5 degrees. Two objects resulted to be of clear extragalactic origin, ... More
Confirmation of persistent radio jets in the microquasar LS 5039Oct 24 2002We present here new observations conducted with the EVN and MERLIN of the persistent microquasar LS 5039 discovered by Paredes et al. (2000) with the VLBA. The new observations confirm the presence of an asymmetric two-sided jet reaching up to 1000 AU ... More
On the multiwavelength spectrum of the microquasar 1E 1740.7-2942Sep 06 2006Context. The microquasar 1E 1740.7-2942 is a source located in the direction of the Galactic Center. It has been detected at X-rays, soft gamma-rays, and in the radio band, showing an extended radio component in the form of a double-sided jet. Although ... More
Episodic gamma-ray and neutrino emission from the low mass X-ray binary GRO J0422+32Feb 01 2013GRO J0422+32 is a member of the class of low-mass X-ray binary (LMXB) sources, discovered during an outburst in 1992. Along the entire episode ($\sim 230$ days) a persistent power-law spectral component extending up to $\sim 1$ MeV was observed. These ... More
Leptonic secondary emission in a hadronic microquasar modelOct 03 2007Context: It has been proposed that the origin of the very high-energy photons emitted from high-mass X-ray binaries with jet-like features, so-called microquasars (MQs), is related to hadronic interactions between relativistic protons in the jet and cold ... More
Massive protostars as gamma-ray sourcesNov 30 2009Massive protostars have associated bipolar outflows with velocities of hundreds of km s$^{-1}$. Such outflows can produce strong shocks when interact with the ambient medium leading to regions of non-thermal radio emission. We aim at exploring under which ... More
Non-Abelian Topological Order from Quantum Organization in Indistinguishable GroupsFeb 14 2014Apr 22 2014I propose that non-Abelian topological order can emerge from the organization of quantum particles into identical indistinguishable copies of the same quantum many-body state. Quantum indistinguishability (symmetrization) of the collectivities leads to ... More
Families of (1,2)-Symplectic M etrics on Full Flag ManifoldsOct 23 2000We obtain new families of (1,2)-symplectic invariant metrics on the full complex flag manifolds F(n). For n > 4, we characterize n-3 different n-dimensional families of (1,2)-symplectic invariant metrics on F(n). Any of these families corresponds to a ... More
Free fermion antibunching in a degenerate atomic Fermi gas released from an optical latticeNov 21 2006Noise in a quantum system is fundamentally governed by the statistics and the many-body state of the underlying particles. Whereas for bosonic particles the correlated noise observed for e.g. photons or bosonic neutral atoms can still be explained within ... More
A possible black hole in the gamma-ray microquasar LS 5039Jul 22 2005Sep 27 2005The population of high energy and very high energy gamma-ray sources, detected with EGRET and the new generation of ground-based Cherenkov telescopes, conforms a reduced but physically important sample. Most of these sources are extragalactic (e.g., blazars), ... More
Realization of the Hofstadter Hamiltonian with ultracold atoms in optical latticesAug 01 2013Sep 07 2013We demonstrate the experimental implementation of an optical lattice that allows for the generation of large homogeneous and tunable artificial magnetic fields with ultracold atoms. Using laser-assisted tunneling in a tilted optical potential we engineer ... More
Zero helicity states in the $LaAlO_3/SrTiO_3$ interfaceSep 05 2015Oct 14 2015We propose a kinetically driven mechanism based on the breaking of the spatial reflection symmetry to describe the magnetic moment and the torque observed by Lu-Li et al. (Ref. 1) for the $LaAlO_3/SrTiO_3$ system. We find that the itinerant electrons ... More
Non-critical holography and four-dimensional CFT's with fundamentalsMay 16 2005Jul 11 2005We find non-critical string backgrounds in five and eight dimensions, holographically related to four-dimensional conformal field theories with N=0 and N=1 supersymmetries. In the five-dimensional case we find an AdS_5 background metric for a string model ... More
A microquasar model applied to unidentified gamma-ray sourcesJan 11 2006Jan 12 2006Among unidentified gamma-ray sources in the galactic plane, there are some that present significant variability and have been proposed to be high-mass microquasars. To deepen the study of the possible association between variable low galactic latitude ... More
Molecular Cloud Turbulence and Star FormationMar 14 2006We review the properties of turbulent molecular clouds (MCs), focusing on the physical processes that influence star formation (SF). MC formation appears to occur during large-scale compression of the diffuse ISM driven by supernovae, magnetorotational ... More
Discovery of a new radio galaxy within the error box of the unidentified gamma-ray source 3EG J1735-1500Jan 24 2003We report the discovery of a new radio galaxy within the location error box of the gamma-ray source 3EG J1735-1500. The galaxy is a double-sided jet source forming a large angle with the line of sight. Optical observations reveal a V ~ 18 magnitude galaxy ... More
EVN and MERLIN observations of microquasar candidates at low galactic latitudesJan 23 2004In an attempt to increase the number of known microquasars, Paredes et al. (2002) have presented a long-term project focused on the search for new objects of this type. They performed a cross-identification between X-ray and radio catalogs under very ... More
Gamma-rays from massive protostarsAug 06 2009Massive protostars have associated bipolar outflows with velocities of hundreds of km/s. Such outflows produce strong shocks when interact with the ambient medium leading to regions of non-thermal radio emission. Under certain conditions, the population ... More
Gamma-ray emission from massive star forming regionsMay 13 2008Recent radio observations support a picture for star formation where there is accretion of matter onto a central protostar with the ejection of molecular outflows that can affect the surrounding medium. The impact of a supersonic outflow on the ambient ... More
Gamma-ray emission from massive young stellar objectsAug 22 2007Massive stars form in dense and massive molecular cores. The exact formation mechanism is unclear, but it is possible that some massive stars are formed by processes similar to those that produce the low-mass stars, with accretion/ejection phenomena occurring ... More
Non-thermal emission from massive YSOs. Exploring the spectrum at high energiesJun 13 2008Thermal radio and X-ray emission has been traditionally associated with the formation of stars. However, in recent years, non-thermal radiation from massive star forming regions has been detected. Synchrotron radio emission and non-thermal X-rays from ... More
Evidence of H alpha periodicities in LS I+61303Sep 14 1999We present the results of analyzing H$\alpha$ spectra of the radio emitting X-ray binary LS I+61303. For the first time, the same 26.5 d radio period is clearly detected in the H$\alpha$ emission line. Moreover, the equivalent width and the peak separation ... More
Wavelet analysis of baryon acoustic structures in the galaxy distributionJan 10 2011Mar 14 2012Baryon Acoustic Oscillations (BAO) are a feature imprinted in the density field by acoustic waves travelling in the plasma of the early universe. Their fixed scale can be used as a standard ruler to study the geometry of the universe. BAO have been previously ... More
Quantum information processing using localized ensembles of nuclear spinsJul 23 2004Jul 23 2004We describe a technique for quantum information processing based on localized en sembles of nuclear spins. A qubit is identified as the presence or absence of a collective excitation of a mesoscopic ensemble of nuclear spins surrounding a single quantum ... More
Results of a search for new microquasars in the GalaxyFeb 02 2004We present here the results of a search for new microquasars at low galactic latitudes, based on a cross-identification between the ROSAT all sky Bright Source Catalog (RBSC) and the NRAO VLA Sky Survey (NVSS) and follow-up observations. The results obtained ... More
Stellar radio astrophysicsFeb 27 2004Radio emission has been detected from all the stages of stellar evolution across the HR Diagram. Its presence reveals both astrophysical phenomena and stellar activity which, otherwise, would not be detectable by other means. The development of large, ... More
LS 5039: a runaway microquasar ejected from the galactic planeJan 15 2002We have compiled optical and radio astrometric data of the microquasar LS 5039 and derived its proper motion. This, together with the distance and radial velocity of the system, allows us to state that this source is escaping from its own regional standard ... More
Molecular Cloud Evolution II. From cloud formation to the early stages of star formation in decaying conditionsAug 17 2006Jan 22 2007We study the formation of giant dense cloud complexes and of stars within them by means of SPH numerical simulations of the mildly supersonic collision of gas streams (``inflows'') in the warm neutral medium (WNM). The resulting compressions cause cooling ... More
Evidence for skyrmions in the high-temperature superconductorsOct 16 2013We claim that the charge density wave recently found by resonant soft x-ray scattering in layered copper oxides is the tetragonal symmetry defined by the distance between neighbor Cu$^{3+}$ ions in the CuO$_2$ layer that determines the critical temperature. ... More
Identifying variable gamma-ray sources through radio observationsJul 21 2004We present preliminary results of a campaign undertaken with different radio interferometers to observe a sample of the most variable unidentified EGRET sources. We expect to detect which of the possible counterparts of the gamma-ray sources (any of the ... More
Study and mitigation of spurious electron emission from cathodic wires in noble liquid time projection chambersJan 22 2018Noble liquid radiation detectors have long been afflicted by spurious electron emission from their cathodic electrodes. This phenomenon must be understood and mitigated in the next generation of liquid xenon (LXe) experiments searching for WIMP dark matter ... More
Morphology of the galaxy distribution from wavelet denoisingAug 15 2005We have developed a method based on wavelets to obtain the true underlying smooth density from a point distribution. The goal has been to reconstruct the density field in an optimal way ensuring that the morphology of the reconstructed field reflects ... More
Interlinguistic similarity and language death dynamicsJan 18 2005We analyze the time evolution of a system of two coexisting languages (Castillian Spanish and Galician, both spoken in northwest Spain) in the framework of a model given by Abrams and Strogatz [Nature 424, 900 (2003)]. It is shown that, contrary to the ... More
Microquasars as high-energy gamma-ray sourcesSep 09 2004Galactic microquasars are certainly one of the most recent additions to the field of high energy astrophysics and have attracted increasing interest over the last decade. However, the high energy part of the spectrum of microquasars is the most poorly ... More
Gamma-ray binaries: microquasars and binary systems with pulsarJan 25 2011Several binary systems have been detected at High Energy (HE, E > 100 MeV) and/or Very High Energy (VHE, E > 100 GeV) gamma rays. Some of them are X-ray binaries in which accretion feeds relativistic radio jets and powers the non-thermal emission (i.e., ... More
AGNs and microquasars as high energy gamma-ray sourcesDec 02 2004The extragalactic analogs of the microquasars, the quasars, are strong gamma-ray emitters at GeV energies. It is expected that microquasars are also gamma-ray sources, because of the analogy with quasars and because theoretical models predict the high-energy ... More
Accelerated detectors and worldsheet horizons in AdS/CFTNov 18 2010Mar 02 2011We use the AdS/CFT correspondence to discuss the response of an accelerated observer to the quantum vacuum fluctuations. In particular, we study heavy quarks probing a strongly coupled CFT by analysing strings moving in AdS. We propose that, in this context, ... More
Intrinsic decoherence and purity in a Bose quantum fluid in a triple well potentialJun 11 2013Feb 10 2014We consider a quantum Bose fluid confined in a triple well potential in 1D within the exact N-body Bose-Hubbard model to investigate the phenomena of intrinsic decoherence and loss of purity. Our study is done by following the time evolution of one-body ... More
Response of photomultiplier tubes to xenon scintillation lightJan 05 2018We present the precision calibration of 35 Hamamatsu R11410-22 photomultiplier tubes (PMTs) with xenon scintillation light centred near 175 nm. This particular PMT variant was developed specifically for the LUX-ZEPLIN (LZ) dark matter experiment. A room-temperature ... More
VHE Gamma-rays from Galactic X-ray Binary SystemsMar 07 2008The detection of TeV gamma-rays from LS 5039 and the binary pulsar PSR B1259-63 by HESS, and from LS I +61 303 and the stellar-mass black hole Cygnus X-1 by MAGIC, provides a clear evidence of very efficient acceleration of particles to multi-TeV energies ... More
Nematic phase transitions in two-dimensional systemsDec 09 2005Simulations of nematic-isotropic transition of liquid crystals in two dimensions are performed using an O(2) vector model characterised by non linear nearest neighbour spin interaction governed by the fourth Legendre polynomial $P\_4$. The system is studied ... More
Gamma rays from compact binary systemOct 24 2008Some of the very high energy (VHE) gamma-ray sources detected with the modern generation of Cherenkov telescopes have been identified with previously known X-ray binary systems. These detections demonstrate the richness of non-thermal phenomena in compact ... More
Chiral Ladders and the Edges of Chern InsulatorsJun 05 2013The realization and detection of topological phases with ultracold atomic gases is at the frontier of current theoretical and experimental research. Here, we identify cold atoms in optical ladders subjected to synthetic magnetic fields as readily realizable ... More
High-energy gamma-ray emission in AGNs and microquasarsSep 06 2006I review here some of the main observational features in microquasars and AGNs as sources of high-energy gamma-rays as well as some of the current models that try to explain the emission in the gamma-ray domain.
High energy processes in microquasarsJan 26 2005Microquasars are X-ray binary stars with the capability to generate relativisticjets. It is expected that microquasars are gamma-ray sources, because of the analogy with quasars and because the theoretical models predict emission at such energy range. ... More
Radio properties of Very High Energy gamma-ray sourcesJun 03 2009Radio observations of very high energy (VHE) gamma-ray sources are fundamental to identify and reveal their nature, as well as to understand the physics behind these energetic sources. I will comment on some characteristics of extragalactic sources detected ... More
Effects of aerogel-like disorder on the critical behavior of O(m)-vector models. Recent simulations and experimental evidencesAug 11 2006We review some results on the effect of a specific type of quenched disorder on well known O(m)-vector models in three dimension. Evidences of changes of criticality in both systems, when confined in aerogel pores, are briefly referenced. The 3DXY model ... More
Three-dimensional Ising model confined in low-porosity aerogels: a Monte Carlo studyApr 26 2006Jun 04 2006The influence of correlated impurities on the critical behaviour of the 3D Ising model is studied using Monte Carlo simulations. Spins are confined into the pores of simulated aerogels (diffusion limited cluster-cluster aggregation) in order to study ... More
Interference of fractionalized quasiparticles in AIII topological insulatorsJul 05 2016Fractionalization in one-dimensional topological insulators has not been yet directly observed. Moreover, novel symmetry classes of topological insulators like the AIII class lack experimental realization. Our work might open possibilities for both challenges. ... More
Phenomenology of gamma-ray emitting binariesFeb 26 2019Gamma-ray emitting binaries (GREBs) are complex systems. Its study became in the last years a major endeavour for the high-energy astrophysics community, both from an observational and a theoretical perspective. Whereas the accumulation of observation ... More
On the Statistics of the Ratio of Non-Constrained Arbitrary α-μ Random Variables: a General Framework and ApplicationsFeb 21 2019In this paper, we derive closed-form exact expressions for the main statistics of the ratio of squared alpha-mu random variables, which are of interest in many scenarios for future wireless networks where generalized distributions are more suitable to ... More
A Note on the String Dual of N=1 SQCD-like TheoriesJan 08 2007In this note we describe how N=1 SQCD-like theories with a large number of flavors can be given a dual description in terms of a string background containing a large number of additional D5-branes. The dual geometries account for the backreaction of the ... More
Multiflavour excited mesons from the fifth dimensionDec 21 2004We study the Regge trajectories and the quark-antiquark energy in excited hadrons composed by different dynamical mass constituents via the gauge/string correspondence. First we exemplify the procedure in a supersymmetric system, D3-D7, in the extremal ... More
Minimum instances of topological matter in an optical plaquetteNov 23 2007We propose experimental schemes to create and probe minimum forms of different topologically ordered states in a plaquette of an optical lattice: Resonating Valence Bond, Laughlin and string-net condensed states. We show how to create anyonic excitations ... More