9 research outputs found
Gravitational field around a time-like current-carrying screwed cosmic string in scalar-tensor theories
In this paper we obtain the space-time generated by a time-like
current-carrying superconducting screwed cosmic string(TCSCS). This
gravitational field is obtained in a modified scalar-tensor theory in the sense
that torsion is taken into account. We show that this solution is comptible
with a torsion field generated by the scalar field . The analysis of
gravitational effects of a TCSCS shows up that the torsion effects that appear
in the physical frame of Jordan-Fierz can be described in a geometric form
given by contorsion term plus a symmetric part which contains the scalar
gradient. As an important application of this solution, we consider the linear
perturbation method developed by Zel'dovich, investigate the accretion of cold
dark matter due to the formation of wakes when a TCSCS moves with speed and
discuss the role played by torsion. Our results are compared with those
obtained for cosmic strings in the framework of scalar-tensor theories without
taking torsion into account.Comment: 21 pages, no figures, Revised Version, presented at the "XXIV-
Encontro Nacional de Fisica de Particulas e Campos ", Caxambu, MG, Brazil, to
appear in Phys. Rev.
Chemical composition and dry matter digestibility of sugar cane oxide treated with calcium
The first Hubble diagram and cosmological constraints using superluminous supernovae
This paper has gone through internal review by the DES collaboration.
It has Fermilab preprint number 19-115-AE and DES
publication number 13387. We acknowledge support from EU/FP7-
ERC grant 615929. RCN would like to acknowledge support from
STFC grant ST/N000688/1 and the Faculty of Technology at the
University of Portsmouth. LG was funded by the European Unionâs
Horizon 2020 Framework Programme under the Marie SkĆodowska-
Curie grant agreement no. 839090. This work has been partially
supported by the Spanish grant PGC2018-095317-B-C21 within
the European Funds for Regional Development (FEDER). Funding
for the DES Projects has been provided by the U.S. Department
of Energy, the U.S. National Science Foundation, the Ministry
of Science and Education of Spain, the Science and Technology
Facilities Council of the United Kingdom, the Higher Education
Funding Council for England, the National Center for Supercomputing
Applications at the University of Illinois at Urbana-Champaign,
the Kavli Institute of Cosmological Physics at the University of
Chicago, the Center for Cosmology and Astro-Particle Physics at
the Ohio State University, the Mitchell Institute for Fundamental
Physics and Astronomy at Texas A&M University, Financiadora
de Estudos e Projetos, Fundacž Ëao Carlos Chagas Filho de Amparo
`a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de
Desenvolvimento CientŽıfico e TecnolŽogico and the MinistŽerio da
CiËencia, Tecnologia e Inovacž Ëao, the Deutsche Forschungsgemeinschaft,
and the Collaborating Institutions in the Dark Energy Survey.
The Collaborating Institutions are Argonne National Laboratory, the
University of California at Santa Cruz, the University of Cambridge,
Centro de Investigaciones EnergÂŽeticas, Medioambientales y Tecnol
ÂŽogicas-Madrid, the University of Chicago, University College
London, the DES-Brazil Consortium, the University of Edinburgh,
the Eidgenšossische Technische Hochschule (ETH) Zšurich, Fermi
NationalAccelerator Laboratory, theUniversity of Illinois atUrbana-
Champaign, the Institut de Ci`encies de lâEspai (IEEC/CSIC), the
Institut de FŽısica dâAltes Energies, Lawrence Berkeley National
Laboratory, the Ludwig-Maximilians Universitšat Mšunchen and the
associated Excellence Cluster Universe, the University of Michigan,
the National Optical Astronomy Observatory, the University of
Nottingham, The Ohio State University, the University of Pennsylvania,
the University of Portsmouth, SLAC National Accelerator
Laboratory, Stanford University, the University of Sussex, Texas
A&M University, and the OzDES Membership Consortium. Based
in part on observations at Cerro Tololo Inter-American Observatory,
National Optical Astronomy Observatory, which is operated by the
Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation.
The DES data management system is supported by the
National Science Foundation under grant numbers AST-1138766
and AST-1536171. The DES participants from Spanish institutions
are partially supported by MINECO under grants AYA2015-
71825, ESP2015-66861, FPA2015-68048, SEV-2016-0588, SEV-
2016-0597, and MDM-2015-0509, some of which include ERDF
funds from the European Union. IFAE is partially funded by the
CERCA program of the Generalitat de Catalunya. Research leading
to these results has received funding from the European Research
Council under the European Union Seventh Framework Programme
(FP7/2007-2013) including ERC grant agreements 240672, 291329,
and 306478.We acknowledge support from the Australian Research
Council Centre of Excellence for All-skyAstrophysics (CAASTRO),
through project number CE110001020, and the Brazilian Instituto
Nacional de CiËencia e Tecnologia (INCT) e-Universe (CNPq grant
465376/2014-2).
This paper has been authored by Fermi Research Alliance, LLC
under Contract No.DE-AC02-07CH11359 with theU.S.Department
of Energy, Office of Science, Office of High Energy Physics. The
United States Government retains and the publisher, by accepting
the paper for publication, acknowledges that the United States
Government retains a non-exclusive, paid-up, irrevocable, worldwide
license to publish or reproduce the published form of this paper,
or allow others to do so, for United States Government purposes.We present the first Hubble diagram of superluminous supernovae (SLSNe) out to a redshift of two, together with constraints
on the matter density, M, and the dark energy equation-of-state parameter, w(âĄp/Ï). We build a sample of 20 cosmologically
useful SLSNe I based on light curve and spectroscopy quality cuts. We confirm the robustness of the peakâdecline SLSN I
standardization relation with a larger data set and improved fitting techniques than previous works. We then solve the SLSN
model based on the above standardization via minimization of the Ï2 computed from a covariance matrix that includes statistical
and systematic uncertainties. For a spatially flat cold dark matter ( CDM) cosmological model, we find M = 0.38+0.24
â0.19,
with an rms of 0.27 mag for the residuals of the distance moduli. For a w0waCDM cosmological model, the addition of SLSNe I
to a âbaselineâ measurement consisting of Planck temperature together with Type Ia supernovae, results in a small improvement
in the constraints of w0 and wa of 4 per cent.We present simulations of future surveys with 868 and 492 SLSNe I (depending on
the configuration used) and show that such a sample can deliver cosmological constraints in a flat CDM model with the same
precision (considering only statistical uncertainties) as current surveys that use Type Ia supernovae, while providing a factor of
2â3 improvement in the precision of the constraints on the time variation of dark energy, w0 and wa. This paper represents the
proof of concept for superluminous supernova cosmology, and demonstrates they can provide an independent test of cosmology
in the high-redshift (z > 1) universe.EU/FP7-ERC grant 615929STFC grant ST/N000688/1Faculty of Technology at the
University of PortsmouthEuropean Unionâs
Horizon 2020 Framework Programme under the Marie SkĆodowska-
Curie grant agreement no. 839090Spanish grant PGC2018-095317-B-C21 within
the European Funds for Regional Development (FEDER)U.S. Department
of EnergyU.S. National Science FoundationMinistry
of Science and Education of SpainScience and Technology
Facilities Council of the United KingdomHigher Education
Funding Council for EnglandNational Center for Supercomputing
Applications at the University of Illinois at Urbana-Champaign,Kavli Institute of Cosmological Physics at the University of
ChicagoCenter for Cosmology and Astro-Particle Physics at
the Ohio State UniversityMitchell Institute for Fundamental
Physics and Astronomy at Texas A&M University, Financiadora
de Estudos e Projetos, FundacĂŁo Carlos Chagas Filho de Amparo
`a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de
Desenvolvimento CientĂfico e TecnolĂłgico and the MinistĂ©rio da
Ciencia, Tecnologia e InovacĂŁoDeutsche ForschungsgemeinschaftCollaborating Institutions in the Dark Energy Survey.National Science Foundation under grant numbers AST-1138766
and AST-1536171.T MINECO under grants AYA2015-
71825, ESP2015-66861, FPA2015-68048, SEV-2016-0588, SEV-
2016-0597, and MDM-2015-0509, some of which include ERDF
funds from the European Union.CERCA program of the Generalitat de Catalunya.European Research
Council under the European Union Seventh Framework Programme
(FP7/2007-2013) including ERC grant agreements 240672, 291329,
and 306478.Australian Research
Council Centre of Excellence for All-skyAstrophysics (CAASTRO),
through project number CE110001020Brazilian Instituto
Nacional de CiËencia e Tecnologia (INCT) e-Universe (CNPq grant
465376/2014-2)Fermi Research Alliance, LLC
under Contract No.DE-AC02-07CH11359 with theU.S.Department
of Energy, Office of Science, Office of High Energy Physic
First cosmology results using SNe Ia from the dark energy survey: analysis, systematic uncertainties, and validation
International audienceWe present the analysis underpinning the measurement of cosmological parameters from 207 spectroscopically classified type Ia supernovae (SNe Ia) from the first three years of the Dark Energy Survey Supernova Program (DES-SN), spanning a redshift range of 0.01
First cosmology results using type Ia supernovae from the Dark Energy Survey: constraints on cosmological parameters
We present the first cosmological parameter constraints using measurements of type Ia supernovae (SNe Ia) from the Dark Energy Survey Supernova Program (DES-SN). The analysis uses a subsample of 207 spectroscopically confirmed SNe Ia from the first three years of DES-SN, combined with a low-redshift sample of 122 SNe from the literature. Our "DES-SN3YR" result from these 329 SNe Ia is based on a series of companion analyses and improvements covering SN Ia discovery, spectroscopic selection, photometry, calibration, distance bias corrections, and evaluation of systematic uncertainties. For a flat LCDM model we find a matter density Omega_m = 0.331 +_ 0.038. For a flat wCDM model, and combining our SN Ia constraints with those from the cosmic microwave background (CMB), we find a dark energy equation of state w = -0.978 +_ 0.059, and Omega_m = 0.321 +_ 0.018. For a flat w0waCDM model, and combining probes from SN Ia, CMB and baryon acoustic oscillations, we find w0 = -0.885 +_ 0.114 and wa = -0.387 +_ 0.430. These results are in agreement with a cosmological constant and with previous constraints using SNe Ia (Pantheon, JLA)
The first Hubble diagram and cosmological constraints using superluminous supernovae
We present the first Hubble diagram of superluminous supernovae (SLSNe) out to a redshift of two, together with constraints on the matter density, ΩM, and the dark energy equation-of-state parameter, w(âĄp/Ï). We build a sample of 20 cosmologically useful SLSNe I based on light curve and spectroscopy quality cuts. We confirm the robustness of the peakâdecline SLSN I standardization relation with a larger data set and improved fitting techniques than previous works. We then solve the SLSN model based on the above standardization via minimization of the Ï2 computed from a covariance matrix that includes statistical and systematic uncertainties. For a spatially flat Î cold dark matter (ÎCDM) cosmological model, we find ΩM=0.38+0.24â0.19â , with an rms of 0.27 mag for the residuals of the distance moduli. For a w0waCDM cosmological model, the addition of SLSNe I to a âbaselineâ measurement consisting of Planck temperature together with Type Ia supernovae, results in a small improvement in the constraints of w0 and wa of 4 per cent. We present simulations of future surveys with 868 and 492 SLSNe I (depending on the configuration used) and show that such a sample can deliver cosmological constraints in a flat ÎCDM model with the same precision (considering only statistical uncertainties) as current surveys that use Type Ia supernovae, while providing a factor of 2â3 improvement in the precision of the constraints on the time variation of dark energy, w0 and wa. This paper represents the proof of concept for superluminous supernova cosmology, and demonstrates they can provide an independent test of cosmology in the high-redshift (z > 1) universe.</p
Compressibilidade do solo e sistema radicular da canaâdeâaçĂșcar em manejo com e sem controle de trĂĄfego
O objetivo deste trabalho foi comparar a capacidade de suporte de carga do solo em ĂĄrea com canaâdeâaçĂșcar colhida mecanicamente sem queima, em sistemas de manejo com e sem controle de trĂĄfego agrĂcola. O controle de trĂĄfego foi feito com ajuste da bitola do trator e transbordo, ou com ajuste da bitola e uso de piloto automĂĄtico. As amostras de solo foram coletadas em cilindros volumĂ©tricos, na soqueira e na entrelinha da cultura (linha de rodado), nas camadas de 0,00-0,10 e 0,20-0,30 m. Avaliou-se a densidade radicular por meio de imagens, obtidas da digitalização de raĂzes coletadas em monĂłlitos de 0,25x0,10x0,10 m. O manejo sem controle de trĂĄfego apresentou maior capacidade de suporte de carga do solo na linha de plantio, nas duas camadas de solo avaliadas, o que indicou maior compactação. Maior densidade radicular ocorreu no manejo com controle de trĂĄfego com ajuste da bitola e piloto automĂĄtico, que permitiu maior capacidade de suporte de carga na linha de rodado e preservou a qualidade estrutural na regiĂŁo da soqueira, com reflexo positivo sobre o desenvolvimento do sistema radicular da canaâdeâaçĂșcar
Multi-messenger Observations of a Binary Neutron Star Merger
International audienceOn 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg(2) at a luminosity distance of Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 . An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over âŒ10 days. Following early non-detections, X-ray and radio emission were discovered at the transientâs position and days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta