toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Bombacigno, F.; Moretti, F.; Boudet, S.; Olmo, G.J. url  doi
openurl 
  Title Landau damping for gravitational waves in parity-violating theories Type Journal Article
  Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 02 Issue 2 Pages 009 - 29pp  
  Keywords Gravitational waves in GR and beyond: theory; modified gravity; gravitational waves / experiments; dark matter experiments  
  Abstract We discuss how tensor polarizations of gravitational waves can suffer Landau damping in the presence of velocity birefringence, when parity symmetry is explicitly broken. In particular, we analyze the role of the Nieh-Yan and Chern-Simons terms in modified theories of gravity, showing how the gravitational perturbation in collisionless media can be characterized by a subluminal phase velocity, circumventing the well-known results of General Relativity and allowing for the appearance of the kinematic damping. We investigate in detail the connection between the thermodynamic properties of the medium, such as temperature and mass of the particles interacting with the gravitational wave, and the parameters ruling the parity violating terms of the models. In this respect, we outline how the dispersion relations can give rise in each model to different regions of the wavenumber space, where the phase velocity is subluminal, superluminal or does not exist. Quantitative estimates on the considered models indicate that the phenomenon of Landau damping is not detectable given the sensitivity of present-day instruments.  
  Address [Bombacigno, F.; Moretti, F.; Olmo, Gonzalo J.] Ctr Mixto Univ Valencia, CSIC, Dept Fis Teor, Carrer Doctor Moliner 50, Valencia 46100, Spain, Email: flavio2.bombacigno@uv.es;  
  Corporate Author Thesis  
  Publisher IOP Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title (up)  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001040875600002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5624  
Permanent link to this record
 

 
Author Cosme, C.; Figueroa, D.G.; Loayza, N. url  doi
openurl 
  Title Gravitational wave production from preheating with trilinear interactions Type Journal Article
  Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 05 Issue 5 Pages 023 - 30pp  
  Keywords physics of the early universe; primordial gravitational waves (theory); gravita-tional waves; sources; particle physics-cosmology connection  
  Abstract We investigate the production of gravitational waves (GWs) during preheating with monomial/polynomial inflationary potentials, considering a trilinear coupling & phi;x2 between a singlet inflaton & phi; and a daughter scalar field x. For sufficiently large couplings, the trilinear interaction leads to an exponential production of x particles and, as a result, a large stochastic GW background (SGWB) is generated throughout the process. We study the linear and non-linear dynamics of preheating with lattice simulations, following the production of GWs through all relevant stages. We find that large couplings lead to SGWBs with amplitudes today that can reach up to h2 �(0) GW <^> 5 & BULL; 10-9. These backgrounds are however peaked at high frequencies fp > 5 & BULL; 106 Hz, which makes them undetectable by current/planned GW observatories. As the amount of GWs produced is in any case remarkable, we discuss the prospects for probing the SGWB indirectly by using constraints on the effective number of relativistic species in the universe Neff.  
  Address [Cosme, Catarina; Figueroa, Daniel G.; Loayza, Nicolas] Univ Valencia CSIC, Inst Fis Corpuscular IFIC, Parc Cientif UV,C-Catedrat Jose Beltran 2, E-46980 Paterna, Spain, Email: catarina.cosme@ific.uv.es;  
  Corporate Author Thesis  
  Publisher IOP Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title (up)  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001038638500007 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 5660  
Permanent link to this record
 

 
Author Zhai, Y.J.; Giare, W.; van de Bruck, C.; Di Valentino, E.; Mena, O.; Nunes, R.C. url  doi
openurl 
  Title A consistent view of interacting dark energy from multiple CMB probes Type Journal Article
  Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 07 Issue 7 Pages 032 - 16pp  
  Keywords cosmological parameters from CMBR; dark energy theory  
  Abstract We analyze a cosmological model featuring an interaction between dark energy and dark matter in light of the measurements of the Cosmic Microwave Background released by three independent experiments: the most recent data by the Planck satellite and the Atacama Cosmology Telescope, and WMAP (9-year data). We show that different combinations of the datasets provide similar results, always favoring an interacting dark sector with a 95% C.L. significance in the majority of the cases. Remarkably, such a preference remains consistent when cross-checked through independent probes, while always yielding a value of the expansion rate H0 consistent with the local distance ladder measurements. We investigate the source of this preference by scrutinizing the angular power spectra of temperature and polarization anisotropies as measured by different experiments.  
  Address [Zhai, Yuejia; Giare, William; van de Bruck, Carsten; Di Valentino, Eleonora] Univ Sheffield, Sch Math & Stat, Hounsfield Rd, Sheffield S3 7RH, England, Email: yzhai13@sheffield.ac.uk;  
  Corporate Author Thesis  
  Publisher IOP Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title (up)  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001066525900001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5673  
Permanent link to this record
 

 
Author ANTARES Collaboration (Albert, A. et al); Alves, S.; Calvo, D.; Carretero, V.; Gozzini, R.; Hernandez-Rey, J.J.; Lazo, A.; Manczak, J.; Pieterse, C.; Real, D.; Saina, A.; Sanchez-Losa, A.; Salesa Greus, F.; Zornoza, J.D.; Zuñiga, J. url  doi
openurl 
  Title Review of the online analyses of multi-messenger alerts and electromagnetic transient events with the ANTARES neutrino telescope Type Journal Article
  Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 08 Issue 8 Pages 072 - 23pp  
  Keywords neutrino astronomy; neutrino detectors  
  Abstract By constantly monitoring a very large portion of the sky, neutrino telescopes are well-designed to detect neutrinos emitted by transient astrophysical events. Real-time searches with the ANTARES telescope have been performed to look for neutrino candidates coincident with gamma-ray bursts detected by the Swift and Fermi satellites, high-energy neutrino events registered by IceCube, transient events from blazars monitored by HAWC, photon-neutrino coincidences by AMON notices and gravitational wave candidates observed by LIGO/Virgo. By requiring temporal coincidence, this approach increases the sensitivity and the significance of a potential discovery. This paper summarises the results of the followup performed of the ANTARES telescope between January 2014 and February 2022, which corresponds to the end of the data-taking period.  
  Address [Albert, A.; Drouhin, D.; Pradier, T.] Univ Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France, Email: dornic@cppm.in2p3.fr  
  Corporate Author Thesis  
  Publisher IOP Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title (up)  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001068854500001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5703  
Permanent link to this record
 

 
Author Amerio, A.; Cuoco, A.; Fornengo, N. url  doi
openurl 
  Title Extracting the gamma-ray source-count distribution below the Fermi-LAT detection limit with deep learning Type Journal Article
  Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 09 Issue 9 Pages 029 - 39pp  
  Keywords gamma ray theory; Machine learning  
  Abstract We reconstruct the extra-galactic gamma-ray source-count distribution, or dN/dS, of resolved and unresolved sources by adopting machine learning techniques. Specifically, we train a convolutional neural network on synthetic 2-dimensional sky-maps, which are built by varying parameters of underlying source-counts models and incorporate the FermiLAT instrumental response functions. The trained neural network is then applied to the Fermi-LAT data, from which we estimate the source count distribution down to flux levels a factor of 50 below the Fermi-LAT threshold. We perform our analysis using 14 years of data collected in the (1, 10) GeV energy range. The results we obtain show a source count distribution which, in the resolved regime, is in excellent agreement with the one derived from cataloged sources, and then extends as dN/dS " S-2 in the unresolved regime, down to fluxes of 5 center dot 10-12 cm-2 s-1. The neural network architecture and the devised methodology have the flexibility to enable future analyses to study the energy dependence of the source-count distribution.  
  Address [Amerio, A.] Univ Valencia, Inst Fis Corpuscular IFIC, Calle Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: aurelio.amerio@ific.uv.es;  
  Corporate Author Thesis  
  Publisher IOP Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title (up)  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001097055700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5785  
Permanent link to this record
 

 
Author ANTARES Collaboration (Albert, A. et al); Alves, S.; Calvo, D.; Carretero, V.; Gozzini, R.; Hernandez-Rey, J.J.; Manczak, J.; Pieterse, C.; Real, D.; Sanchez-Losa, A.; Salesa Greus, F.; Zornoza, J.D.; Zuñiga, J. url  doi
openurl 
  Title Limits on the nuclearite flux using the ANTARES neutrino telescope Type Journal Article
  Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 01 Issue 1 Pages 012 - 19pp  
  Keywords dark matter detectors; neutrino detectors  
  Abstract In this work, a search for nuclearites of strange quark matter by using nine years of ANTARES data taken in the period 2009-2017 is presented. The passage through matter of these particles is simulated taking into account a detailed description of the detector response to nuclearites and of the data acquisition conditions. A down-going flux of cosmic nuclearites with Galactic velocities (beta = 10(-3)) was considered for this study. The mass threshold for detecting these particles at the detector level is 4 x 10(13) GeV/c(2). Upper limits on the nuclearite flux for masses up to 10(17) GeV/c(2) at the level of similar to 5 x 10(-17) cm(-2) s(-1) sr(-1) are obtained. These are the first upper limits on nuclearites established with a neutrino telescope and the most stringent ever set for Galactic velocities.  
  Address [Drouhin, D.; Pradier, T.] Univ Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France  
  Corporate Author Thesis  
  Publisher IOP Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title (up)  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001090397800002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5790  
Permanent link to this record
 

 
Author Boudet, S.; Bombacigno, F.; Moretti, F.; Olmo, G.J. url  doi
openurl 
  Title Torsional birefringence in metric-affine Chern-Simons gravity: gravitational waves in late-time cosmology Type Journal Article
  Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 01 Issue 1 Pages 026 - 28pp  
  Keywords Gravitational waves in GR and beyond: theory; modified gravity; Cosmological perturbation theory in GR and beyond; Exact solutions; black holes and black hole thermodynamics in GR and beyond  
  Abstract In the context of the metric-affine Chern-Simons gravity endowed with projective invariance, we derive analytical solutions for torsion and nonmetricity in the homogeneous and isotropic cosmological case, described by a flat Friedmann-Robertson-Walker metric. We discuss in some details the general properties of the cosmological solutions in the presence of a perfect fluid, such as the dynamical stability and the emergence of big bounce points, and we examine the structure of some specific solutions reproducing de Sitter and power law behaviours for the scale factor. Then, we focus on first-order perturbations in the de Sitter scenario, and we study the propagation of gravitational waves in the adiabatic limit, looking at tensor and scalar polarizations. In particular, we find that metric tensor modes couple to torsion tensor components, leading to the appearance, as in the metric version of Chern-Simons gravity, of birefringence, characterized by different dispersion relations for the left and right circularized polarization states. As a result, the purely tensor part of torsion propagates like a wave, while nonmetricity decouples and behaves like a harmonic oscillator. Finally, we discuss scalar modes, outlining as they decay exponentially in time and do not propagate.  
  Address [Boudet, S.] Univ Trento, Dipartimento Fis, Via Sommar 14, I-38123 Povo, TN, Italy, Email: simon.boudet@unitn.it;  
  Corporate Author Thesis  
  Publisher IOP Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title (up)  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001090397800016 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5791  
Permanent link to this record
 

 
Author Alencar, G.; Estrada, M.; Muniz, C.R.; Olmo, G.J. url  doi
openurl 
  Title Dymnikova GUP-corrected black holes Type Journal Article
  Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 11 Issue 11 Pages 100 - 23pp  
  Keywords Exact solutions; black holes and black hole thermodynamics in GR and beyond; GR black holes; modified gravity; quantum black holes  
  Abstract We consider the impact of Generalized Uncertainty Principle (GUP) effects on the Dymnikova regular black hole. The minimum length scale introduced by the GUP modifies the energy density associated with the gravitational source, referred to as the Dymnikova vacuum, based on its analogy with the gravitational counterpart of the Schwinger effect. We present an approximated analytical solution (together with exact numerical results for comparison) that encompasses a wide range of black hole sizes, whose properties crucially depend on the ratio between the de Sitter core radius and the GUP scale. The emergence of a wormhole inside the de Sitter core in the innermost region of the object is one of the most relevant features of this family of solutions. Our findings demonstrate that these solutions remain singularity free, confirming the robustness of the Dymnikova regular black hole under GUP corrections. Regarding energy conditions, we find that the violation of the strong, weak, and null energy conditions which is characteristic of the pure Dymnikova case does not occur at Planckian scales in the GUP corrected solution. This contrast suggests a departure from conventional expectations and highlights the influence of quantum corrections and the GUP in modifying the energy conditions near the Planck scale.  
  Address [Alencar, G.; Olmo, Gonzalo J.] Univ Fed Ceara, Dept Fis, Caixa Postal 6030,Campus Pici, BR-60455760 Fortaleza, Ceara, Brazil, Email: geova@fisica.ufc.br;  
  Corporate Author Thesis  
  Publisher IOP Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title (up)  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001121623400017 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5868  
Permanent link to this record
 

 
Author Chakraborty, S.; Gupta, A.; Vanvlasselaer, M. url  doi
openurl 
  Title Anomaly induced cooling of neutron stars: a Standard Model contribution Type Journal Article
  Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 10 Issue 10 Pages 030 - 23pp  
  Keywords neutron stars; neutrino theory  
  Abstract Young neutron stars cool via the emission of neutrinos from their core. A precise understanding of all the different processes producing neutrinos in the hot and degenerate matter is essential for assessing the cooling rate of such stars. The main Standard Model processes contributing to this effect are nu bremsstrahlung, mURCA among others. In this paper, we investigate another Standard Model process initiated by the Wess-Zumino-Witten term, leading to the emission of neutrino pairs via N gamma -> N nu nu over bar . We find that for proto-neutron stars, such processes with degenerate neutrons can be comparable and even dominate over the typical and well-known cooling mechanisms.  
  Address [Chakraborty, Sabyasachi] Indian Inst Technol, Dept Phys, Kanpur 208016, India, Email: sabyac@iitk.ac.in;  
  Corporate Author Thesis  
  Publisher IOP Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title (up)  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001116545800007 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5872  
Permanent link to this record
 

 
Author Forconi, M.; Ruchika; Melchiorri, A.; Mena, O.; Menci, N. url  doi
openurl 
  Title Do the early galaxies observed by JWST disagree with Planck's CMB polarization measurements? Type Journal Article
  Year 2023 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.  
  Volume 10 Issue 10 Pages 012 - 16pp  
  Keywords cosmological parameters from CMBR; high redshift galaxies; CMBR polarisation; reionization  
  Abstract The recent observations from the James Webb Space Telescope have led to a surprising discovery of a significant density of massive galaxies with masses of M >= 10(10.5)M(circle dot) at redshifts of approximately z similar to 10. This corresponds to a stellar mass density of roughly rho* similar to 10(6)M(circle dot) Mpc(-3). Despite making conservative assumptions regarding galaxy formation, this finding may not be compatible with the standard.CDM cosmology that is favored by observations of CMB Anisotropies from the Planck satellite. In this paper, we confirm the substantial discrepancy with Planck's results within the.CDM framework. Assuming a value of is an element of = 0.2 for the efficiency of converting baryons into stars, we indeed find that the.CDM model is excluded at more than 99.7% confidence level (C.L.). An even more significant exclusion is found for is an element of similar to 0.1, while a better agreement, but still in tension at more than 95%, is obtained for is an element of = 0.32. This tension, as already discussed in the literature, could arise either from systematics in the JWST measurements or from new physics. Here, as a last-ditch effort, we point out that disregarding the large angular scale polarization obtained by Planck, which allows for significantly larger values of the matter clustering parameter sigma(8), could lead to better agreement between Planck and JWST within the.CDM framework. Assuming.CDM and no systematics in the current JWST results, this implies either an unknown systematic error in current large angular scale CMB polarization measurements or an unidentified physical mechanism that could lower the expected amount of CMB polarization produced during the epoch of reionization. Interestingly, the model compatible with Planck temperature-only data and JWST observation also favors a higher Hubble constant H-0 = 69.0 +/- 1.1 km/s/Mpc at 68% C.L., in better agreement with observations based on SN-Ia luminosity distances.  
  Address [Forconi, Matteo; Ruchika; Melchiorri, Alessandro] Univ Roma La Sapienza, Phys Dept, Ple Aldo Moro 2, I-00185 Rome, Italy, Email: matteo.forconi@roma1.infn.it;  
  Corporate Author Thesis  
  Publisher IOP Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title (up)  
  Series Volume Series Issue Edition  
  ISSN 1475-7516 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:001142721200001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5903  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records:
ific federMinisterio de Ciencia e InnovaciĆ³nAgencia Estatal de Investigaciongva