A5105820764- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Cosmology and Gravitation Theories
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Galaxies: Formation, Evolution, Phenomena
- Astrophysics and Star Formation Studies
- Atomic and Subatomic Physics Research
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Astro and Planetary Science
- Atmospheric Ozone and Climate
- Particle Detector Development and Performance
- Scientific Research and Discoveries
- Radioactive Decay and Measurement Techniques
- Radiation Therapy and Dosimetry
- History and Developments in Astronomy
- Quantum, superfluid, helium dynamics
- Relativity and Gravitational Theory
- Nuclear Physics and Applications
- Quantum Electrodynamics and Casimir Effect
- Nuclear physics research studies
Laboratoire d'Annecy-le-Vieux de Physique Théorique
2009-2024
Centre National de la Recherche Scientifique
2005-2024
Université Grenoble Alpes
2018-2024
Université Savoie Mont Blanc
1996-2022
Institut National de Physique Nucléaire et de Physique des Particules
2005-2011
Laboratoire de Physique Nucléaire et de Hautes Énergies
2005-2007
Laboratoire de Physique Théorique
1995-2006
Université Paris 8
2005-2006
Sorbonne Université
2005-2006
Université Paris Cité
2006
We present distance measurements to 71 high redshift type Ia supernovae discovered during the first year of 5-year Supernova Legacy Survey (SNLS). These events were detected and their multi-color light-curves measured using MegaPrime/MegaCam instrument at Canada-France-Hawaii Telescope (CFHT), by repeatedly imaging four one-square degree fields in bands, as part CFHT (CFHTLS). Follow-up spectroscopy was performed VLT, Gemini Keck telescopes confirm nature measure redshift. With this data...
We calculate the antiproton flux due to relic neutralino annihilations, in a two-dimensional diffusion model compatible with stable and radioactive cosmic ray nuclei. find that uncertainty primary induced by propagation parameters alone is about two orders of magnitude at low energies, it mainly determined lack knowledge thickness diffusive halo. On contrary, different dark matter density profiles do not significantly alter flux: Novarro-Frenk-White distribution produces fluxes which are...
(ABRIDGED) We show that Type Ia supernovae (SNe Ia) are formed within both very young and old stellar populations, with observed rates depend on the mass mean star-formation (SFRs) of their host galaxies. Models where SN rate depends solely galaxy ruled out 99% confidence. Our analysis is based 100 spectroscopically-confirmed SNe Ia, plus 24 photometrically-classified events, all from Supernova Legacy Survey (SNLS) distributed over 0.2
Cosmic-ray nuclei fluxes are expected to be measured with high precision in the near future. For instance, high-quality data on antiproton component could give important clues about nature of astronomical dark matter. A very good understanding different aspects cosmic-ray propagation is therefore necessary. In this paper, we use constraints diffusion parameters. Propagation studied semianalytical solutions a model, and new analytical for radioactively produced species. Our model includes...
Cosmic ray antiprotons provide an important probe for the study of galactic Dark Matter, as they could be produced by exotic sources. On other hand, are anyway standard nuclear reactions cosmic nuclei on interstellar matter. This process is responsible a background flux that must carefully determined to estimate detectability hypothetical signal. Estimates this suffer from potential uncertainties various origins. The propagation depends several physical characteristics Galaxy which poorly...
We present new techniques for improving the efficiency of supernova (SN) classification at high redshift using 64 candidates observed Gemini North and South during first year Supernova Legacy Survey (SNLS). The SNLS is an ongoing 5 project with goal measuring equation state dark energy by discovering following over 700 high-redshift SNe Ia data from Canada-France-Hawaii Telescope Survey. achieve improvement in SN spectroscopic confirmation rate: 71% are now confirmed as Ia, compared to 54%...
Aims. This paper gives a description of new online database and associated tools (data selection, data export, plots, etc.) for charged cosmic-ray measurements. The experimental setups (type, flight dates, techniques) from which the originate are included in database, along with references to all relevant publications.
<i>Context. <i/> Secondary positrons are produced by spallation of cosmic rays within the interstellar gas. Measurements have been typically expressed in terms positron fraction, which exhibits an increase above 10 GeV. Many scenarios proposed to explain this feature, among them some additional primary originating from dark matter annihilation Galaxy.<i>Aims. The PAMELA satellite has provided high quality data that enabled accuracy statistical analyses be made, showing fraction extends up...
We present the activities of `New Physics' working group for `Physics at TeV Colliders' workshop (Les Houches, France, 5--23 June, 2017). Our report includes new physics studies connected with Higgs boson and its properties, direct search strategies, reinterpretation LHC results in building viable models computational tool developments.
We present a measurement of the distant Type Ia supernova rate derived from first two years Canada -- France Hawaii Telescope Supernova Legacy Survey. observed four one-square degree fields with typical temporal frequency ~ 4 observer-frame days over time spans 158 to 211 per season for each field, breaks during full moon. used 8-10 meter-class telescopes spectroscopic followup confirm our candidates and determine their redshifts. Our starting sample consists 73 spectroscopically verified...
We present a method for selecting high-redshift type Ia supernovae (SNe Ia) located via rolling SN searches. The technique, using both color and magnitude information of events from only 2-3 epochs multi-band real-time photometry, is able to discriminate between SNe core collapse SNe. Furthermore, the Ia, accurately predicts redshift, phase light-curve parameterization these based on pre-maximum-light data. demonstrate effectiveness technique simulated survey core-collapse SNe, where...
Recent measurements of cosmic ray proton and helium spectra show a hardening above few hundreds GeV. This excess is hard to understand in the framework conventional models Galactic production propagation. We propose here explain this anomaly by presence local sources (myriad model). Cosmic propagation described as diffusion process taking place inside two-zone magnetic halo. calculate fluxes at Earth between 50 GeV 100 TeV. Improving over similar analysis, we consistently derive these into...
We consider neutralino annihilation in dense extragalactic systems known to be dominated by dark matter, particular M87 and several local dwarf spheroidal galaxies. These annihilations can produce energetic gamma rays which may visible atmospheric \ifmmode \check{C}\else \v{C}\fi{}erenkov telescopes. explore the supersymmetric parameter space, compute expected flux of coming from these objects. It is shown that some parts space lead a signal observable with next generation telescopes,...
We compare the rise times of nearby and distant Type Ia supernovae (SNe Ia) as a test for evolution using 73 high-redshift spectroscopically-confirmed SNe from first two years five year Supernova Legacy Survey (SNLS) published observations SN. Because ``rolling'' search nature SNLS, our measurement is approximately 6 more precise than previous studies, allowing sensitive between supernovae. Adopting simple $t^2$ early-time model (as in studies), we find that rest-frame $B$ fiducial SN at...
In a previous study (Maurin et al. 2001), we explored the set of parameters describing diffusive propagation cosmic rays (galactic convection, reacceleration, halo thickness, spectral index and normalization diffusion coefficient), identified those giving good fit to measured ratio. This is now extended take into account sixth free parameter, namely sources. We use an updated version our code where reacceleration term comes from standard minimal models. The goal this paper present general...
In a previous analysis, Maurin et al. (2001) have constrained several parameters of the cosmic ray diffusive propagation (the diffusion coefficient normalization K0 and its spectral index δ, halo half-thickness L, Alfvén velocity Va, galactic wind Vc) using stable nuclei. second paper (Donato 2002), these were shown to reproduce observed antiproton spectrum with no further adjustment. present paper, we extend analysis β-radioactive nuclei 10Be, 26Al 36Cl. These species will be particularly...
Context.The small-scale distribution of dark matter in galactic halos is poorly known. Several studies suggest that it could be very clumpy, which paramount importance when investigating the annihilation signal from exotic particles (e.g. supersymmetric or Kaluza-Klein).
<i>Context. <i/>Propagation of charged cosmic-rays in the Galaxy depends on transport parameters, whose number can be large depending propagation model under scrutiny. A standard approach for determining these parameters is a manual scan, leading to an inefficient and incomplete coverage parameter space.<i>Aims. <i/>In analyzing data from forthcoming experiments, more sophisticated strategy required. An automated statistical tool used, which enables full space provides sound determination...
Primordial black holes (pbhs) have motivated many studies since it was shown that they should evaporate and produce all kinds of particles (Hawking [CITE]). Recent experimental measurements cosmic rays with great accuracy, theoretical investigations on the possible formation mechanisms detailed evaporation processes revived interest in such astrophysical objects. This article aims to use latest developments antiproton propagation models (Maurin et al. [CITE]; Donato [CITE]) together new data...
Extra dimensions offer new ways to address long-standing problems in beyond-the-standard-model particle physics. In some classes of extra-dimensional models, the lightest Kaluza-Klein is a viable dark matter candidate. this work, we study indirect detection via its annihilation into antiprotons. We use sophisticated galactic cosmic ray diffusion model whose parameters are fully constrained by an extensive set experimental data. find that models with universal extra remain unconstrained...
The propagation of Galactic cosmic ray nuclei having energies between 100 MeV/nuc and several PeV/nuc is strongly believed to be diffusive nature. particles emitted by a source located in the disk do not pervade whole Galaxy, but are rather confined smaller region whose spatial extension related height halo, wind spallation rate. Following pioneering work Jones (1978), this paper presents general study on origin rays, with particular attention role spallations wind. This question different,...
Cosmic Ray nuclei in the energy range 100 MeV/nuc - GeV/nuc provide crucial information about physical properties of Galaxy. They can also be used to answer questions related astroparticle physics. This paper reviews results obtained this direction, with a strong bias towards work done by authors at {\sc lapth}, isn} and iap}. The propagation these is studied quantitatively framework semi-analytical two-zone diffusion model taking into account effect galactic wind, diffuse reacceleration...
The annihilation of dark matter (DM) in the Galaxy could produce specific imprints on spectra antimatter species Galactic cosmic rays, which be detected by upcoming experiments such as PAMELA and AMS02. Recent studies show that presence substructures can enhance signal a ``boost factor'' not only depends energy, but is intrinsically statistical property distribution DM inside Milky Way. We investigate scenario consist $\ensuremath{\sim}100$ ``minispikes'' around intermediate-mass black...