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  • E6: Gamma-Ray Bursts as Multi-messengers | UnivEarthS
    but a direct proof of this model is still lacking The high energy part of the GRB spectrum The observation by the Fermi LAT of several GRB photons with energies reaching 50 100 GeV in the source frame is an encouraging sign for GRB detections with the next generation of instruments operating in the GeV and TeV domain The extrapolation of Fermi LAT spectral measurements to the VHE domain is difficult due to the limited knowledge of GRB properties at these energies see Gehrels Razzaque Frontiers of Physics 2013 In particular it remains unclear whether the hard component observed in the spectra of several bright Fermi GRBs is a common property at GeV energies In addition intrinsic spectral cut offs similar to the case of GRB 090926A are expected at 1 100 GeV energies and are strongly related to the value of the GRB jet Lorentz factor For these reasons current estimates of the GRB detection rate by future TeV experiments like CTA suffer from important uncertainties and range from 0 5 to 2 GRBs per year Inoue et al Astropart Phys 43 252 2013 Nonetheless during the lifetime of SVOM a few but invaluable GRB detections are thus expected in the 0 05 0 5 TeV range from CTA especially in the light of the recent bright GeV afterglow detected for GRB 130427A Tam et al ApJ 77 L13 2013 Joint time resolved spectral analyses based on SVOM and CTA data will also help to pinpoint the acceleration and emission processes occurring in GRB jets Studies of the GRB prompt emission phase from sub MeV to sub TeV energies can help to distinguish between leptonic and hadronic models and to investigate the possibility of GRBs being a source of ultra high energy cosmic rays and answer the long standing question of the origin of the cosmic rays observed on Earth with energies larger than 10 10 GeV GRBs and the new messengers To date neutrino and gravitational wave signals detected by current experiments could not be correlated with any precise astrophysical source Thanks to their short duration and their high flux GRBs are the best electromagnetic counterpart candidates and a simultaneous detection would represent the start of a new era for those two research fields namely the astronomy era Neutrinos Neutrinos are unique messengers to study the high energy Universe as they are neutral and stable interact weakly and therefore travel directly from their point of creation to the Earth without absorption Neutrinos could play an important role in understanding the mechanisms of cosmic ray acceleration and their detection from a cosmic source would be a direct evidence of the presence of hadronic acceleration Indeed HE neutrinos are produced in a beam dump scenario via meson mainly pion π decay when the accelerated hadrons protons or nuclei interact with ambient matter or dense photon fields The emitted neutrinos typically have an energy which is about 10 of the energy of the interacting protons The production of neutrinos of 10

    Original URL path: http://www.univearths.fr/en/e6-gamma-ray-bursts-multi-messengers?quicktabs_menu_e6_en=0 (2015-10-10)
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  • Gamma-Ray Bursts in the Multi-messenger Era workshop | UnivEarthS
    holes on their environment Frontier projects Earth as a living planet From the Big Bang to the future Universe Support au PCCP The transient catastrophic Universe Interface projects Geoparticles Fundamental physics and Geophysics in space From dust to planets Former Interface projects Formation and early evolution of Planetary systems The youth of cosmic rays and their emergence in the interstellar clouds Gamma ray instrumentation development Young team project Experimental geophysics Valorization project Data distribution visualisation and cloud computing PUBLICATIONS EDUCATIONAL Nanosatellite student project IGOsat UnivEarthS JOB OPPORTUNITY Experimental Dark Matter Search Post Doctoral Research Fellow IGOSat internship PhD position Effect of the North South dichotomy on the thermal structure and evolution of Mars Search this site October Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Sign in Password forgotten Home Gamma Ray Bursts in the Multi messenger Era workshop 20 08 2014 A workshop entitled Gamma Ray Bursts in the Multi messenger Era has bee organized in Paris from june 16th to 19th 2014 at IPGP During the four days

    Original URL path: http://www.univearths.fr/en/gamma-ray-bursts-multi-messenger-era-workshop (2015-10-10)
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  • E7: Advanced time series analysis: application to Microscope data | UnivEarthS
    29 30 Sign in Password forgotten Home PROJECTS Exploratory Projects Advanced time series analysis E7 Advanced time series analysis application to Microscope data Cosmology and fundamental physics Presentation Team Results experimence News Advanced time series analysis application to Microscope data Context The Weak Equivalence Principle WEP states the equality between the inertial mass and the gravitational mass universality of free fall and is a cornerstone of General Relativity GR It can be tested with the Eötvös parameter which is zero if the WEP exactly holds proportional to the difference of the accelerations felt by two bodies made of different materials in the same gravity field Physics beyond GR e g string theory inspired gravity theories may explain the accelerated expansion of the Universe and solve the dark energy problem In this case we predict a WEP violation between 10 18 and 10 13 while the current experimental limits are 10 13 The existing experiments on Earth are reaching their limits so it is important to test the WEP in space MICROSCOPE a French Space Agency mission expected to launch in 2016 will improve the current limits by 2 orders of magnitude Microscope MICROSCOPE French for Drag free micro satellite for the Observation of the Equivalence Principle is made of two ultrasensitive cylindrical electrostatic differential accelerometers The first one consists of two coaxial test masses made of the same material Pt and is used to check for systematics the second one consists of two coaxial test masses made of different material Pt and Ti and will effectively test the WEP A violation of the Equivalence Principle is measured as the difference in acceleration experienced by the proof masses as they orbit the Earth Measurement principle the WEP is tested along a given axis A WEP violation results in a signal at

    Original URL path: http://www.univearths.fr/en/e7-advanced-time-series-analysis-application-microscope-data?mini=node%2F333%2F2015-09 (2015-10-10)
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  • E7: Advanced time series analysis: application to Microscope data | UnivEarthS
    29 30 31 Sign in Password forgotten Home PROJECTS Exploratory Projects Advanced time series analysis E7 Advanced time series analysis application to Microscope data Cosmology and fundamental physics Presentation Team Results experimence News Advanced time series analysis application to Microscope data Context The Weak Equivalence Principle WEP states the equality between the inertial mass and the gravitational mass universality of free fall and is a cornerstone of General Relativity GR It can be tested with the Eötvös parameter which is zero if the WEP exactly holds proportional to the difference of the accelerations felt by two bodies made of different materials in the same gravity field Physics beyond GR e g string theory inspired gravity theories may explain the accelerated expansion of the Universe and solve the dark energy problem In this case we predict a WEP violation between 10 18 and 10 13 while the current experimental limits are 10 13 The existing experiments on Earth are reaching their limits so it is important to test the WEP in space MICROSCOPE a French Space Agency mission expected to launch in 2016 will improve the current limits by 2 orders of magnitude Microscope MICROSCOPE French for Drag free micro satellite for the Observation of the Equivalence Principle is made of two ultrasensitive cylindrical electrostatic differential accelerometers The first one consists of two coaxial test masses made of the same material Pt and is used to check for systematics the second one consists of two coaxial test masses made of different material Pt and Ti and will effectively test the WEP A violation of the Equivalence Principle is measured as the difference in acceleration experienced by the proof masses as they orbit the Earth Measurement principle the WEP is tested along a given axis A WEP violation results in a signal

    Original URL path: http://www.univearths.fr/en/e7-advanced-time-series-analysis-application-microscope-data?quicktabs_menu_e7_en=0 (2015-10-10)
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  • Workshop "Données manquantes" | UnivEarthS
    the Big Bang to the future Universe Support au PCCP The transient catastrophic Universe Interface projects Geoparticles Fundamental physics and Geophysics in space From dust to planets Former Interface projects Formation and early evolution of Planetary systems The youth of cosmic rays and their emergence in the interstellar clouds Gamma ray instrumentation development Young team project Experimental geophysics Valorization project Data distribution visualisation and cloud computing PUBLICATIONS EDUCATIONAL Nanosatellite student project IGOsat UnivEarthS JOB OPPORTUNITY Experimental Dark Matter Search Post Doctoral Research Fellow IGOSat internship PhD position Effect of the North South dichotomy on the thermal structure and evolution of Mars Search this site October Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Sign in Password forgotten Home Workshop Données manquantes 02 03 2015 We are pleased to announce that we are organizing a Missing Data Workshop in Physics which will be held in Nice France from 11th to 12th May 2015 The aim of this workshop is to bring together experts in image processing and researchers in physics astrophysics

    Original URL path: http://www.univearths.fr/en/workshop-donnees-manquantes (2015-10-10)
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  • Contribution | UnivEarthS
    the future Universe Support au PCCP The transient catastrophic Universe Interface projects Geoparticles Fundamental physics and Geophysics in space From dust to planets Former Interface projects Formation and early evolution of Planetary systems The youth of cosmic rays and their emergence in the interstellar clouds Gamma ray instrumentation development Young team project Experimental geophysics Valorization project Data distribution visualisation and cloud computing PUBLICATIONS EDUCATIONAL Nanosatellite student project IGOsat UnivEarthS JOB

    Original URL path: http://www.univearths.fr/en/contribution (2015-10-10)
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  • Former Exploratory projects | UnivEarthS
    Universe Support au PCCP The transient catastrophic Universe Interface projects Geoparticles Fundamental physics and Geophysics in space From dust to planets Former Interface projects Formation and early evolution of Planetary systems The youth of cosmic rays and their emergence in the interstellar clouds Gamma ray instrumentation development Young team project Experimental geophysics Valorization project Data distribution visualisation and cloud computing PUBLICATIONS EDUCATIONAL Nanosatellite student project IGOsat UnivEarthS JOB OPPORTUNITY Experimental

    Original URL path: http://www.univearths.fr/en/former-exploratory-projects?mini=node%2F333%2F2015-09 (2015-10-10)
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  • E1 : Formation of dunes and climate on Titan | UnivEarthS
    on Earth Mars ie sublimation and Titan ie cohesion Planetary sciences By combining the skills regarding the analysis of observations of planetary surfaces and atmospheres AIM laboratory with skills developed within IPGP regarding numerical modelling of complex geophysical systems the project aims to analyze the dynamics of sedimentary bedforms on Titan Leader and co leader of the work package Sébastien Rodriguez Associate Professor AIM University Paris Diderot phone 33 0 1 69 08 80 56 email sebastien rodriguez cea fr web Clément Narteau Associate Professor HDR IPGP University Paris Diderot phone 33 0 1 83 95 74 23 email narteau ipgp fr web www ipgp fr narteau Non permanent members of the team and collaborators Amandine Garcia PhD student AIM phone 33 0 1 69 08 80 56 email amandine garcia cea fr Antoine Lucas Postdoc CNES AIM phone email antoine lucas cea fr Xin Gao PhD student IPGP phone 33 0 1 83 95 77 76 email gao ipgp fr Lü Ping Postdoc IPGP phone 33 0 1 83 95 74 02 email lvping ipgp fr Sylvain Courrech du Pont Associate Professor MSC Lab University Paris Diderot phone 33 0 1 57 27 62 84 email sylvain courrech univ paris diderot fr web 1 Deserts Growth and stability of star dunes under the effect of multidirectional flows Towards a better understanding of the orientation modes of dune crests Star dunes are giant dunes whose ramifications extend in many directions From numerical models taking into account the multidirectional wind regimes researchers from the Institut de Physique du Globe de Paris IPGP CNRS and the Laboratory of Matter and Complex Systems CNRS MSC have shown that star dunes could be considered as a superposition of longitudinal dunes The direction and the rate of growth of each branch can then be predicted as a function of the configuration of the flow and the quantity of sand available These new results open new perspectives for the analysis of dune fields and sediment transport in many geophysical environments subjected to multidirectional flows Star dunes can be described as a tangle of dune forms whose crests and sides of avalanche spread in multiple directions They usually consist of a central dome which grows on smaller structures with apparently no preferred orientation Probably because these star dunes are very large more than 100 m high and apparently highly complex their shapes and dynamics have been until now very few studied The majority of these studies rely on secondary flows which depending on the topography create recirculation currents in directions oblique to the main flow These flows are the cause of the growth of arms and would control the final shape of the dunes The new findings go against this hypothesis and clearly show that star dunes can be produced from the sediment transport associated with each of the main directions of flow This work also shows that the ramifications of star dunes have morphological characteristics height width and growth velocity depending on the wind conditions For

    Original URL path: http://www.univearths.fr/en/e1-formation-dunes-and-climate-titan?mini=node%2F333%2F2015-09 (2015-10-10)
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