The importance of including a thorough search for the potential use of astronomy in the examination of any culture is discussed. Educational strategies are included that can enable scholars to add related research knowledge that will enable them to augment their studies in this pursuit.
What can be learned from astronomy in culture is examined and the importance of including such research as...
In the context of a warm inflation scenario, we explore the effect of a primordial magnetic field on a charged scalar field potential.
Using a combination of Smooth Particle hydrodynamics and Adaptive Mesh Refinement simulations of galaxy mergers, with sub-parsecs scale resolution, we have study both the mass transport process onto the massive black holes throughout a galactic merger and especially, the posible black holes coalescence at galactic center. The final coalescence of these black holes lead to gravitational...
The study of resolved stellar populations in nearby galaxies outside of the Local Group has come within reach with the new generation of extremely large telescopes, featuring primary mirror diameters on the order of 30 meters. ELT, the European Extremely Large Telescope, is currently being built at the Armazones site in the Atacama desert of Chile. From the instrumentation suite for the ELT,...
Stars conserve in their atmospheres, to a large extent, the chemical composition of the gas cloud from which they formed. The chemical compositions of old, metal-poor stars in the halo of our galaxy can hence be used for reconstructing the chemical enrichment history of the Milky Way, and studying the nucleosynthesis processes that contributed to the enrichment. For example, a unique abundance...
The possibility that the spontaneous symmetry breaking in the Standard Model (SM) may be generated by the Top-Higgs Yukawa interaction (which determines the so called “second minimum” in the SM) is investigated. A former analysis about a QCD action only including the Yukawa interaction of a single quark with a scalar field is here extended. We repeat the calculation done in that study of the...
We compute the neutral pion mass dependence on a magnetic field in the weak field approximation at one-loop order. The calculation is carried out within the linear sigma model coupled to quarks and using Schwinger's proper-time representation for the charged particle propagators. We find that the neutral pion mass decreases with the field strength provided the boson self-coupling magnetic...
We studied some exact configurations for the three-dimensional massive multi-gravity theory called "Viel-dreibein gravity". We find AdS wave solutions (which reflect the main dynamic properties of the model) and analyze their asymptotic behavior. In addition, we explore the existence of black holes in the context of this theory.
The interaction of ultra-high-energy cosmic rays (UHECRs) with pervasive photon fields generates associated cosmogenic fluxes of neutrinos and photons due to photohadronic and photonuclear processes taking place in the intergalactic medium. We perform a fit of the UHECR spectrum and composition measured by the Pierre Auger Observatory for four source emissivity scenarios: power-law redshift...
In this contribution, I present the study of the effect of higher derivative terms in the effective potential of a scalar field theory. Preliminary results indicate that quantum correction coming from the higher derivative terms make the curvature of the effective potential, near the origin, becomes flatter. I will discuss how this result could be interesting within a warm inflation scenario.
We review the surface charge method in the Einstein-Cartan formalism and study in particular the role of torsion in the computation of charges. An example in 2+1 gravity is worked out explicitly and some advances in the Einstein-Cartan-Dirac theory are presented.
Abstract The use of a metric independent measure of integration in the action opens new possibilities for constructing globally scale invariant theories, since the new measure can be assigned a different scaling transformation than the usual metric dependent measure sqrt(-g). There are various ways to construct a density that can serve as a metric independent measure of integration, from the...
In this talk I will present a novel theory with the aim of describing the dynamics of ultrarelativistic fluids considering dissipative effects up to second order. The problem of achieving a covariant relativistic extension of the equations that describe non-relativistic dissipative fluids constitutes a very active area of current research, given that a well-posed and causal theory of viscous...
We investigate possible finite-volume effects on baryon number susceptibilities of strongly interacting matter. Assuming that a hadronic and a deconfined phase both contribute to the thermodynamic state of a finite system due to fluctuations, it is found that the resulting shapes of the net-baryon number distributions deviate significantly from the infinite volume limit for a given ...
Recently, the HADES experiment at GSI has provided preliminary data on the directed flow, $v_1$ elliptic flow, $v_2$ and triangular flow, $v_3$ of protons in Au+Au reactions at a beam energy of 1.23 A GeV. Here we present a theoretical discussion of these flow harmonics within the UrQMD transport approach. We show that all flow harmonics, including the triangular flow, provide a consistent...
The HADES experiment at GSI will soon provide data on the production and properties of ∆ baryons from Au+Au reactions at 1.23 AGeV. Using the UrQMD model, we predict the yield and spectra of ∆ resonances. In addition we show that one expects to observe a mass shift of the ∆ resonance on the order of 40 MeV in the reconstructable ∆ mass distribution. This mass shift can be understood in terms...
Recently we succeeded, by introducing an interaction between the gluon mean field (presented by the a function of the Polyakov loop) and quarks, to reproduce the lattice equation of state for zero chemical potential with the Polyakov-Nambu-Jona-Lasinio model. Also, entropy density, interaction measure, energy density and the speed of sound are quite nicely reproduced. Even the first...
We extend the Parton-Hadron-String Dynamics (PHSD) transport approach in the partonic sector by explicitly calculating the total and differential partonic scattering cross sections as a function of temperature $T$ and baryon chemical potential $\mu_B$ on the basis of the effective propagators and couplings from the Dynamical QuasiParticle Model (DQPM) that is matched to reproduce the equation...
In this talk, we discuss UrQMD phase-space coalescence calculations for the production of deuterons. We compare with available data for various reactions from the GSI/FAIR energy regime up to LHC. It is found that the production process of deuterons, as reflected in their rapidity and transverse momentum distributions in p+p, p+A and A+A collisions at a beam energies starting from the GSI...
Within the context of AdS/CFT Correspondence, we first compute one-loop infrared (IR) divergences of 7D Einstein Gravity in a certain Poincaré-Einstein background metric. We compute then the one-loop ultraviolet (UV) divergences of 6D Conformal Gravity on the boundary. We verify the equality of the above results that stems from the IR-UV connection of the duality dictionary. Key ingredients...
The generalized SU(2) Proca theory is the only modified gravity theory, nowadays, able to accommodate in a natural way a configuration of vector fields which is compatible with the homogeneous and isotropic nature of our Universe. In previous works, we have been able to uncover a self-tuning mechanism that drives an eternal slow-roll inflationary period for an ample spectrum of initial...
Lie-Backlund transformations have been used to extend the criteria proposed by Ayón-Beato and Velázquez-Rodríguez for characterizing the residual symmetries of the gravitational ansatz developed according to Lie-point transformations. We found that non-local Lie-Backlund transformations allows us to obtain the more general residual symmetries of the metric. We present the generalized criteria...
In this work we use the correspondence between a field theory in de Sitter space in 4-dimensions and the dual conformal field theory in an euclidean space in 3-dimensions, to compute the form of two and three point correlation functions of scalar-tensor perturbations. To this end, we use an inflationary model, in which the inflaton field is interacting with a vector field trough the term...
In this contribution I will review the state of the art measurements for the symmetry energy from both astrophysical and terrestrial laboratories. In particular the recent detection of gravitational radiation from the GW170817 event shed light on the properties of the neutron star equation of state, thus comprising both the study of the symmetry energy and stellar radius. Furthermore, I shall...
Stueckelberg-Horwitz-Piron (SHP) theory is a framework for posing classical and quantum relativistic physics in canonical form with an external parameter of evolution $\tau$. SHP electrodynamics generalizes Maxwell theory by allowing the four-vector potential to depend on $\tau$ and introducing a scalar gauge potential $a_5(x,\tau)$ associated with this $\tau$-dependence. As a result, current...
A recent finding, based on empirical data of 153 rotationally supported galaxies, with very different morphologies, masses, sizes, and gas fractions, revealed that the baryonic and the dark matter in galaxies are strongly coupled, such that, if the first is known, the second follows and vice versa. Here, we propose a completely theoretical analysis of the dynamics of rotationally supported...
The combined effects of both the standard magnetic dipole model and the composite neutron superfluid vortex model on the energy loss rate of neutron stars and pulsar spin down are simultaneously taken into account to study the evolution of neutron stars on the P-Pdot diagram. The evolution path of each neutron star is dictated by a particular mechanism in our hybrid model in different...
When a supernova explodes, a blast wave is generated and propagates into the ambient medium, whereas the deceleration of the ejecta by the ambient medium induces an inward-propagating shock wave, the so-called reverse shock (RS). If the RSs can efficiently accelerate cosmic-rays, then they can be important production sites of heavy-element cosmic-rays. We present evidence for efficient...
The quasi periodic oscillations (QPOs) observed in the soft-gamma repeaters are generally considered as a results of the global oscillations of the neutron stars. In this study, we first take into account the torsional oscillations excited in the tube and bubble phases, which can be excited independently of the oscillations in the phases of spherical and cylindrical nuclei, and successfully...
Gravitational wave signal from core-collapse supernova is the key to understand the mechanism of core-collapse supernovae. The evolution of the frequency of the signal tells us the property of neutron star and information of the accretion flow near the neutron star. In this study, I will introduce the gravitational waveform based on our recent 3D simulations and discuss what information...
The Facility for Antiproton and Ion Research, FAIR, is presently being constructed adjacent to the existing accelerator complex of the GSI Helmholtz Centre for Heavy Ion Research at Darmstadt/Germany, expanding the research goals and technical possibilities substantially. The worldwide unique accelerator and experimental facilities of FAIR will open the way for a broad spectrum of...
A modified theory of gravity, avoiding singularities in the standard theory of gravitation, has been developed by Hess \& Greiner, known as the pseudo-complex theory of gravitation. The pc-GR theory shows remarkable observational differences with respect to standard GR. The intensity profiles are significantly different between both theories, which is a rare phenomenon in astrophysics. This...
The observation predictions of the pseudo-complex General Relativity, related to the structure of an accretion disk, are compared to the reported observations of the Event Horizon Telescope.
One century after the discovery of cosmic rays, the origin of ultra high energy cosmic rays still remains enigmatic. Taking data since 2004, the Pierre Auger Collaboration has been expanding our knowledge about these cosmic particles with energies much higher than what LHC can achieve. Although some intriguing questions have been answered, some of the mystery still persists. The focus of this...
In this work we study the intrinsic CPT violation in the neutrino oscillations phenomena produced by quantum decoherence as sub-leading effect. In the usual representation, we find that only fifteen elements of the decoherence matrix violate the CPT symmetry intrinsically. We find exact solutions for the CPT asymmetry function in vacuum . We define an observable $\mathcal{R}$ to make...
In this work we study the initial value problem of a non-linear extension of classical Electromagnetism, known as "Force-Free Electrodynamics" (FFE). The FFE equations describe the dynamics of a diluted plasma near the event horizon of a rotating black hole. In these astrophysical regions, magnetic fields dominate the dynamics when compared with the matter that constitutes those plasmas,...
Magnetic fields introduce an anisotropy in compact stars’ equations of state by splitting the pressure into two components, one parallel and the other perpendicular to the magnetic field. This suggests the necessity of using structure equations accounting for the axial symmetry of the magnetized system. We consider an axially symmetric metric in spherical coordinates, the $\gamma$-metric, and...
We study magnetic field effects on the Equations of State (EoS) and the structure (mass-radius relation) of Bose-Einstein Condensate (BEC) stars, i.e. a compact object composed by a gas of interacting spin one bosons formed up by the pairing of two neutrons. To include magnetic field in the star description we suppose that particle-field and particle-particle interactions are independent, and...
We study the thermodynamic properties of a neutral vector boson gas in presence of a constant magnetic field at finite temperature. The study has been done considering relativistic and non-relativistic bosons. In general, one of the most outstanding properties of magnetized bosonic systems is the occurrence of Bose-Einstein condensation (BEC) and Bose-Einstein ferromagnetism: in the condensed...
When studying the structure of magnetized compact objects, the anisotropy in their equations of state (EoS), due to the magnetic field, must be taken into account. This anisotropy consists in the splitting of the pressure in two components, one parallel and the other perpendicular to the magnetic field. In this work, we compare the size and shape of magnetized strange quark stars using three...
We study the propagation of photon in magnetized vacuum and medium, taking into account radiative corrections. We describe both time delay and Faraday rotation, with the aim of applying the results to astrophysical context.
The existence of black holes has its analytical argumentation in Einstein's field equations. The first solution of general relativity that would characterize a black hole was found by Schwarzschild in 1916. Since then, these cosmic objects are being studied and investigated in their various variants: Scwartzshild, Kerr, Reissner-Nordström, Kerr-Newman, and others. The no-hair theorem states...
We investigated the claim that galaxy NGC 1052-DF2 lacks dark matter. For this purpose, we constructed a novel, theory-based computer simulation of the dynamical interaction of matter and dark matter in a prototypical ellipsoid galaxy and utilized it to predict the distributions of dark matter in a galaxy as a function of the galaxy’s core radius and maximal rotation velocity. We ran the...
A correspondence between the Equivalence principle and the homogeneity of the universe is discussed. We show that under the Newtonian gravity, translation of co-moving coordinates in a uniformly expanding universe defines a new accelerated frame. A consistency condition for the invariance of this transformation yields the second Friedman equation. All these symmetries are lost when we modify...
We present the state of research devoted to investigate the consequences of a formerly proposed regular solution at the origin for the Einstein-Klein-Gordon equations. We implement a match with the Schwarzschild solutions with a zero scalar field outside a spherical region. The configuration of fields are used as a first step in an iterative process to calculate the vacuum expectation value of...
In this work a mathematical model for aquatic photosynthesis, modified by some of us to include particulate ionizing radiation, is used to assess the perturbations that muons coming from neutron star mergers could make to this biological process. It is then shown that neutron star mergers not too far from inhabited rocky planets have the potential to considerably deplete their aquatic...
There is a growing interest in the exam and analysis of results in the ALICE, ATLAS and CMS detectors in asymmetric systems (pPb) due to the possibilities of establishing some references for PbPb collisions and to gain insight into the behavior of the medium itself. The analysis of data in both cases can allow the understanding of the PDFs under different regimes. The study of the initial...
Starting from the fact that vacuum pressure orthogonal to a constant magnetic field is negative, whereas along the field is positive, we estimate the shift of frequency for radiation moving in these directions to first order in α at small fields as compared to the Schwinger critical field Bc, and suggest ideas for its experimental test. For fields of order of or greater than 2Bc we briefly...
In this work we obtained an anisotropic Neutron Star solution by a gravitational decoupling of sources. More precisely, we implement a method known as Minimal Geometric Deformation which allows to extended isotropic solutions to anisotropic domains with appropriated matching conditions. We have performed analytical calculations to show that, in this approach, the anisotropic solution has...
After the first detection of Gravitational Waves (GWs) lead to win the Nobel of Physics, characterizing the parameters of the systems creating these events have become more important to shed light on our knowledge of the Universe. In this work, we aim to follow the scientific procedure used by the LIGO-VIRGO interferometer's network to characterize the physical parameters describing the event...
Commonly used in astrophysics, DD2 is a relativistic mean-field equation of state (EoS) with density-dependent couplings parametrized to nuclei data. It reproduces successfully the properties of nuclear matter up to saturation density as well as neutron star masses observations, chiral effective field theory, and symmetry energy constraints. A known caveat of DD2 is the atypical behavior of...
Here we summarized our recent work on evolutions of magnetic field and spin-down of neutron stars mainly focusing on magnetars, X/gamma-ray pulsar PSR J1640-4631 with high braking index n=3.15 (3) and the high-magnetic-field pulsar PSR J1734-3333 with low braking index n=0.9(2). Our work includes the following three parts: (1) Based on the estimated ages of their potentially associated...
In this work, we study the neutrinos diffusion into the hybrid neutron star, after a phase transition from hadronic to quark matter in proto-neutron stars. We calculate the neutrino luminosity and signal features during the cooling of the hybrid neutron star. We use the MIT bag model for quark matter description, taking into account the effect of strong interactions in the perturbative regime...
In this talk I will review the method of estimation of tidal deformabilities of compact stars and present results for pure hadronic as well as hybrid stars that include the mass twins case. Then I will discuss the impact of the nuclear symmetry energy in the determination of the compact star radius.In particular, the recent detection of gravitational radiation from the GW170817 event shed...
The broadening of the transversal momentum (pT) spectrum, the so called Cronin effect, is traditionally explained as a consequence of the initial state interaction at partonic level. It also is a signature of the parton dynamic previous to the fragmentation. In this contribution we will focus on the nuclear modification factor having in mind, that the dilepton production avoid the...
Synchrotron Light, or Radiation, is a type of electromagnetic radiation that spans a wide range of the electromagnetic spectrum – from infrared light, to ultraviolet radiation and x-rays. Synchrotron light is produced when charged particles, accelerated to speeds approaching the speed of light, have their trajectory deflected by magnetic fields. The light we see – produced by the sun, by lamps...
Magnetars are a kind of pulsars powered by magnetic field energy. Part of the X-ray luminosities of magnetars in quiescence have a thermal origin and can be fitted by a blackbody with temperature about kT ~ 0.3–1 keV, much higher than the typical values for rotation-powered pulsars. The observation and theoretical study of magnetars is one of hot topics in the field of pulsars. Combined with...
