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Colloque national DARK ENERGY - 2ieme édition

23–25 oct. 2018
Institut d'Astrophysique de Paris
Fuseau horaire Europe/Paris

Contacts

Liste des Contributions

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  1. 1. orateur invité : Le problème de l'énergie noire
    Philippe Brax (IPHT Saclay)
    23/10/2018 10:30
  2. 2. orateur invité : BAO et RSD avec BOSS/DESI
    Christophe Yeche (CEA Irfu/SPP)
    23/10/2018 11:10
  3. 3. The Dark Side of Gravity and the Acceleration of the Universe
    Frederic Henry-Couannier
    23/10/2018 11:50
  4. 6. Cosmology with a varying vacuum refractive index
    Xavier Sarazin (LAL), François COUCHOT (CNRS/IN2P3/LAL)
    23/10/2018 12:10
  5. 5. Orateur invité : Résultats de Planck
    Valeria Pettorino (CEA Paris-Saclay, Departement of Astrophysics, CosmoStat Lab)
    23/10/2018 14:00
  6. 4. A microscopic model for an emergent cosmological constant
    Alejandro Perez (LPNHE), Dr Daniel Sudarsky (UNAM), Prof. James D. Bjorken (SLAC )
    23/10/2018 14:40
  7. 9. Time dependent dark energy
    Maxim Khlopov (APC and MEPHI)
    23/10/2018 15:00
  8. 16. orateur invité : Les défis informatiques des grands relevés
    Dominique Boutigny (LAPP)
    23/10/2018 15:20
  9. 30. Combining large-scale surveys and the CMB: the why and the how
    Stéphane Ilic (Institut de Recherche en Astrophysique et Planétologie)
    23/10/2018 16:30
  10. 24. Cosmology with galaxy surveys : the impact of non-linearity
    Fabien Lacasa (Université de Genève)
    23/10/2018 16:50
  11. 31. orateur invité : Machine learning et cosmologie
    Dr Emille Ishida (LPC-UCA)
    23/10/2018 17:10
  12. 33. Testing gravity and dark energy with galaxy-galaxy lensing and redshift-space distortion in the CFHT Stripe-82 and CFHTLS
    Eric Jullo (LAM)
    23/10/2018 17:50
  13. 12. orateur invité : L'expérience DES
    Dr Emmanuel Bertin (IAP)
    24/10/2018 09:00
  14. 39. orateur invité : Tracing the Universe with the XMM X-ray survey
    Marguerite PIERRE (CEA Saclay)
    24/10/2018 09:40
  15. 13. temps de discussion Collaboration grands projets
    Cecile Renault (LPSC)
    24/10/2018 10:20
  16. 23. orateur invité : The effect of backreaction in cosmology: some challenges
    Prof. Nick Kaiser (ENS)
    24/10/2018 11:10
  17. 17. Can laboratory experiments help to characterize Dark Energy?
    Aurelien Hees (SYRTE - Observatoire de Paris), Dr Michel Abgrall (SYRTE, Observatoire de Paris), Dr Sebastien Bize (SYRTE, Observatoire de Paris), Dr Pacome Delva (SYRTE, Observatoire de Paris), Dr Jocelyne Guéna (SYRTE, Observatoire de Paris), Dr Olivier Minazzoli (Artemis, OCA and CSM), Dr Benjamin Roberts (SYRTE, Observatoire de Paris), Dr Etienne Savalle (SYRTE, Observatoire de Paris), Yevgeny Stadnik (Johannes Gutenberg University of Mainz)
    24/10/2018 11:50
  18. 7. Testing for the environmental dependence of the growth rate
    Ixandra Achitouv
    24/10/2018 12:10
  19. 19. orateur invité : Résultats de Virgo/LIGO
    Dr Edward Porter (APC Paris)
    24/10/2018 14:00
  20. 20. Systèmes binaires : l'approche de la théorie effective
    Adrien Kuntz (CPT Marseille)
    24/10/2018 14:40
  21. 21. E pur si muove! A proposal for a real-time detection of our acceleration through space
    Christian Marinoni (Centre de Physique Théorique, Marseille)
    24/10/2018 15:00
  22. 22. orateur invité : Conséquences des ondes gravitationnelles sur l'énergie noire
    Filippo Vernizzi (IPhT - CEA Saclay)
    24/10/2018 15:20
  23. 18. Théories tenseur-scalaire: où en sommes nous?
    Karim Noui (LMPT Tours)
    24/10/2018 16:00
  24. 10. orateur invité : Simulations numériques pour la cosmologie
    Dr Yann Rasera (LUTH)
    24/10/2018 16:50
  25. 26. Cosmic Homogeneity as a standard Ruler
    Pierros Ntelis (Astroparticule et Cosmology Group)
    24/10/2018 17:30
  26. 25. orateur invité : La distribution des galaxies comme sonde cosmologique
    Sylvain de la Torre (LAM)
    24/10/2018 17:50
  27. 62. Plan
    24/10/2018 19:40
  28. 27. orateur invité : Nouvelles du projet LSST
    Emmanuel Gangler (LPC)
    25/10/2018 09:00
  29. 28. A deep learning approach for the classification of supernovae and the estimation of photometric redshifts
    Johanna Pasquet (CPPM)
    25/10/2018 09:40
  30. 29. Results on extensions to LamdaCDM models with Dark Energy Survey
    Dr Agnes Ferte (Jet Propulsion Laboratory)
    25/10/2018 10:00
  31. 8. Hubble Constant Controversy and astrophysical bias
    Mickael Rigault (LPC)
    25/10/2018 10:20
  32. 11. orateur invité : Limites du système solaire et implications + Microscope
    Agnes FIENGA (Institut UTINAM)
    25/10/2018 11:10
  33. 14. SUGAR : A New Model of Type Ia Supernovae for Cosmological Analyses
    Pierre-François Léget (Stanford University)
    25/10/2018 12:00
  34. 35. Les amas dans le scenario LCDM
    Alain Blanchard (IRAP , OMP), Stéphane Ilic (Institut de Recherche en Astrophysique et Planétologie), ziad sakr (IRAP : Institut de Recherche en Astrophysique et Planétologie)
    25/10/2018 12:20
  35. 38. The interplay between Dark energy & modified gravity on the amplitude of matter fluctuations discrepancy between CMB and Galaxy Clusters
    Dr Ziad Sakr (IRAP : Institut de Recherche en Astrophysique et Planétologie)
    25/10/2018 14:20
  36. 32. Bayesian analysis of peculiar velocity measurements
    Romain Graziani (IPNL)
    25/10/2018 14:40
  37. 63. Probing oscillating cosmic field with neutrons
    Guillaume Pignol (LPSC)
    25/10/2018 15:00
  38. 36. orateur invité : Nouvelles du projet Euclid
    M. Françis Bernardeau (IAP)
    25/10/2018 15:20
  39. 37. Temps de discussion: Action nationale dark energy
    Alain Blanchard (IRAP , OMP)
    25/10/2018 16:00
  40. 55. A deep learning approach for the classification of supernovae and the estimation of photometric redshifts
    Johanna Pasquet (CPPM)

    Future large surveys like the Large Synoptic Survey Telescope (LSST) aim to increase the precision and accuracy of observational cosmology. In particular, LSST will observe a large quantity of well-sampled type Ia supernovae that will be one of the major probe of dark energy. However the spectroscopic follow-up for the identification of supernovae and the estimation of redshift will be...

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  41. 41. A microscopic model for an emergent cosmological constant
    Prof. Alejandro Perez (Centre de Physique Theorique)

    We argue that discreteness at the Planck scale (naturally expected to arise from quantum gravity) might manifest in the form of minute violations of energy-momentum conservation of the matter degrees of freedom when described in terms of (idealized) smooth fields on a smooth spacetime. In the context of applications to cosmology such `energy diffusion' from the low energy matter degrees of...

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  42. 48. Can laboratory experiments help to characterize Dark Energy?
    Dr Aurelien Hees (SYRTE, Observatoire de Paris)

    In several theoretical scenarios, a scalar field is introduced to model dark energy. While some properties of this scalar field can be constrained by cosmological observations, certain properties like its coupling with the standard model fields can be searched for with local experiments such as the ones testing for the universality of free fall and the ones using atomic clocks. Such...

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  43. 56. Combiner les grands relevés avec le CMB: pourquoi et comment // Combining large-scale surveys and the CMB: the why and the how
    Stéphane Ilic (Institut de Recherche en Astrophysique et Planétologie)

    Grâce aux mesures de lentillage gravitationnel et de clustering des galaxies, la prochaine génération de grands relevés (Euclid, LSST) posera des contraintes sans précédent sur l'Univers récent. D'autre part, des observations CMB de haute qualité (Planck et futures expérience) sont capables d'imposer des contraintes strictes sur l'Univers primordial. Je montrerai comment la combinaison et la...

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  44. 15. Combining large-scale surveys and the CMB: the why and the how
    Stéphane Ilic (Institut de Recherche en Astrophysique et Planétologie)
  45. 58. Cosmic Homogeneity as a standard Ruler
    Pierros Ntelis (Astroparticule et Cosmology Group)

    In the era of the upcoming stage IV surveys, the sky will be more revealing than ever. In this talk, I will put the homogeneity scale in the general cosmological context. I will show how one can use the homogeneity scale as a standard ruler to learn about the large scale structures.

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  46. 43. Cosmology with a varying vacuum refractive index
    Xavier Sarazin (LAL)

    As initially proposed by H.A. Wilson, then R.H. Dicke, the curved spacetime in a stationary gravitational field can be equivalently interpreted as being due to a spatial change of both the vacuum refractive index and the inertial masses in a Euclidean metric. Dicke further extended this framework to explain the cosmological redshift, assuming a flat and static Euclidean metric but a vacuum...

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  47. 57. Cosmology with galaxy surveys : the impact of non-linearity
    Fabien Lacasa (Université de Genève)

    One of the main challenges for cosmological analysis of future galaxy surveys is the non-linearity of the evolution of the large scale structure (LSS). Among the consequences of this non-linearity is the development of non-Gaussianity of the density field. And this non-Gaussianity yields new covariance terms for our observables, additional to the classical Gaussian variance that we have been...

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  48. 59. E pur si muove! A proposal for a real-time detection of our acceleration through space
    Christian Marinoni (Centre de Physique Théorique, Marseille)

    High-precision astrometric experiments might constrain our proper acceleration through space via real-time observations of the change in the aberration of sources at cosmic distances.
    The cosmological component of this aberration drift signal, the non-inertial motion generated by the large-scale distribution of matter, can in principle be detected by
    astrometric surveys. It can provide...

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  49. 46. Hubble Constant Controversy and astrophysical bias
    Dr Mickael Rigault (LPC)

    I will present the Hubble Constant controversy, that is, the different direct or indirect measurements of the Hubble Constant and how some are in significant tension. Then I'll present our current work on astrophysical bias in Type Ia Supernova distance measurements and explain how such effect could explain the aforementioned tension.

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  50. 61. Les amas dans le scenario LCDM.
    Alain BLANCHARD (IRAP , OMP)

    Le modèle LCDM est un succès remarquable de la cosmologie moderne, rendant compte des principales observations du champ cosmologique, ses six paramètres de base étant maintenant mesurés avec une précision de l'ordre du pourcent. L'abondance des amas détectés par effet SZ est toutefois très en deçà des prédictions du modèle normalisé aux fluctuations mesurées par Planck. L'origine de cette...

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  51. 34. Orateur invité : ?
  52. 51. Results on extensions to LamdaCDM models with Dark Energy Survey
    Dr Agnes Ferte (Jet Propulsion Laboratory)

    The Dark Energy Survey is one of the largest ongoing survey probing the late universe, specially through galaxy clustering and weak gravitational lensing. The data from the first year of DES observations were used to constrain the LambdaCDM model in 1708.01530, combining clustering and weak lensing measurements from the same experiment for the first time. We used this combination of data to...

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  53. 44. SUGAR : A New Model of Type Ia Supernovae for Cosmological Analyses
    Dr Pierre-François Léget (Stanford University)

    Type Ia Supernova (SNIa) distance measurement for cosmology is based on a well-established observational paradigm that two main effects explain their variabilities in luminosity: stretch (link to intrinsic properties), and color (link mainly to dust extinction). However, after correcting the luminosity of both stretch and color, an intrinsic scatter in luminosity and a correlation of Hubble...

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  54. 52. Systèmes binaires : l'approche de la théorie effective
    Adrien Kuntz (CPT Marseille)

    Dans cette présentation, je parlerai de la théorie effective de Goldberger et Rothstein pour obtenir les équations régissant un système binaire. Je montrerai comment elle peut être adaptée à une théorie tenseur-scalaire en mettant en avant les points sur lesquelles ces théories diffèrent de la relativité générale.

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  55. 53. Testing a curvature model using Fisher forecasts for a Euclid-like spectroscopic Survey
    M. Safir Yahia-Cherif (IRAP)

    One of the main prediction of inflationary cosmology is the spatial flatness of the universe. The combination of observed CMB fluctuations with SNIa observations and BAO leads to a prediction of the spatial curvature parameter lower than 1e-4. Observations have shown the acceleration of the expansion of the universe revealing the existence of two dark component : the dark matter and the dark...

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  56. 45. Testing for the environmental dependence of the growth rate
    Dr Ixandra Achitouv (Observatoire de Paris )

    The growth rate of cosmic structures is a powerful quantity to probe gravitational interactions and dark energy. In the late-time Universe the growth rate becomes non-linear, making it more difficult to probe, but also makes it in principle a source of additional cosmological information than its linear counterpart. In this talk, I will discuss why it becomes interesting to probe the growth...

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  57. 54. Testing gravity and dark energy with galaxy-galaxy lensing and redshift-space distortion in the CFHT Stripe-82 and CFHTLS
    Eric Jullo (LAM)

    The combination of GGL and RSD allow to break the degeneracy between the growth rate parameter $f$ and the matter density $\Omega_m$. In this talk, I will present our results obtained with the BOSS/CMASS sample at redshift $z=0.57$, and the weak-lensing over an area of 338 deg$^2$. Using an ensemble of joint lensing and clustering lightcones, we also characterize the statistical properties of...

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  58. 40. The Dark Side of Gravity and the Acceleration of the Universe
    frederic henry-couannier

    Dark Gravity theories are extensions of General Relativity aiming at a stable anti-gravitational sector. The most natural extension of GR in presence of a flat non dynamical background turns out to be such a Dark Gravity theory and it is able to reproduce GR predictions extremely well in many sectors except that it avoids true Black Hole Horizon as well as Big-Bang singularity. The symmetries...

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  59. 60. The interplay between Dark energy & modified gravity on the amplitude of matter fluctuations discrepancy between CMB and Galaxy Clusters.
    Dr Ziad SAKR (IRAP - USJ)

    In the frame of the dark energy colloquium, we investigate the impact of a dark energy different from fiducial $\Lambda$CDM, on a discrepancy on the amplitude of matter fluctuation $\sigma_8$ found between local and deep probes. In particular between local, X ray, or near universe, SZ detected cluster counts samples and deep CMB temperature and polarization angular correlation spectrums.
    We...

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  60. 50. Théories tenseur-scalaire: où en sommes nous?
    Karim Noui (LMPT Tours)

    Les théories tenseur-scalaire offrent un cadre formidable pour tester les éventuelles limites de la relativité générale. Elles sont des modifications de la théorie d'Einstein qui pourraient rendre compte de la présence d'énergie noire dans l'univers par exemple.
    Je vous propose de présenter tout d'abord la construction d'une très grande classe de théories tenseur-scalaire qui a fortement été...

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  61. 47. Time dependent dark energy
    Prof. Maxim Khlopov (APC and MIFI)

    Taking apart cosmological constant, being constant by definition, physics of dark energy may lead to its time dependence. In the simplest case time dependence of the homogeneously distributed comological energy can be implemented in the model with cosmological term and unstable dark matter, decaying after the first objects are formed and contributing the homogeneously distributed energy...

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