81 research outputs found
M-theory on `toric' G_2 cones and its type II reduction
We analyze a class of conical G_2 metrics admitting two commuting isometries,
together with a certain one-parameter family of G_2 deformations which
preserves these symmetries. Upon using recent results of Calderbank and
Pedersen, we write down the explicit G_2 metric for the most general member of
this family and extract the IIA reduction of M-theory on such backgrounds, as
well as its type IIB dual. By studying the asymptotics of type II fields around
the relevant loci, we confirm the interpretation of such backgrounds in terms
of localized IIA 6-branes and delocalized IIB 5-branes. In particular, we find
explicit, general expressions for the string coupling and R-R/NS-NS forms in
the vicinity of these objects. Our solutions contain and generalize the field
configurations relevant for certain models considered in recent work of Acharya
and Witten.Comment: 45 pages, references adde
Martian Eolian Science: Recent Advances, Remaining Questions, and Roadmap for Future In Situ Investigations
We review remaining critical questions in Mars eolian science, summarize needed in situ measurements, and offer a roadmap for future in situ investigations
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
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 Union’s
Horizon 2020 Framework Programme under the Marie Skłodowska-
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, Fundac¸ ˜ao Carlos Chagas Filho de Amparo
`a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de
Desenvolvimento Cient´ıfico e Tecnol´ogico and the Minist´erio da
Ciˆencia, Tecnologia e Inovac¸ ˜ao, 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 Energ´eticas, Medioambientales y Tecnol
´ogicas-Madrid, the University of Chicago, University College
London, the DES-Brazil Consortium, the University of Edinburgh,
the Eidgen¨ossische Technische Hochschule (ETH) Z¨urich, Fermi
NationalAccelerator Laboratory, theUniversity of Illinois atUrbana-
Champaign, the Institut de Ci`encies de l’Espai (IEEC/CSIC), the
Institut de F´ısica d’Altes Energies, Lawrence Berkeley National
Laboratory, the Ludwig-Maximilians Universit¨at M¨unchen 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 Ciˆencia 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(≡p/ρ). We build a sample of 20 cosmologically
useful SLSNe I based on light curve and spectroscopy quality cuts. We confirm the robustness of the peak–decline 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 χ2 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
−0.19,
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 ‘baseline’ 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
2–3 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 Union’s
Horizon 2020 Framework Programme under the Marie Skłodowska-
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, Fundacão Carlos Chagas Filho de Amparo
`a Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de
Desenvolvimento Científico e Tecnológico and the Ministério da
Ciencia, Tecnologia e InovacãoDeutsche 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 Ciˆencia 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
Composição centesimal e teor de nitrato em cinco cultivares de alface produzidas sob cultivo hidropônico
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(≡p/ρ). We build a sample of 20 cosmologically useful SLSNe I based on light curve and spectroscopy quality cuts. We confirm the robustness of the peak–decline 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 χ2 computed from a covariance matrix that includes statistical and systematic uncertainties. For a spatially flat Λ cold dark matter (ΛCDM) cosmological model, we find ΩM=0.38+0.24−0.19, 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 ‘baseline’ 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 ΛCDM model with the same precision (considering only statistical uncertainties) as current surveys that use Type Ia supernovae, while providing a factor of 2–3 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
The structures of N- and O-glycosidic carbohydrate chains of chondroitin sulfate proteoglycan isolated from the media of the human aorta
- …