The New Standard Model of the Universe

The new concordance model in agreement with observations: ΛWDM (Lambda-dark energy- Warm Dark Matter). Recently, Warm (keV scale) Dark Matter emerged impressively over CDM (Cold Dark Matter) as the leading Dark Matter candidate. Astronomical evidence that Cold Dark Matter (LambdaCDM) and its proposed tailored cures do not work at galactic and small scales is staggering. LambdaWDM solves naturally the problems of LambdaCDM and agrees remarkably well with the observations at galactic and small as well as large and cosmological scales. In contrast, LambdaCDM simulations only agree with observations at large scales. In the context of this new Dark Matter situation, which implies novelties in the astrophysical, cosmological and keV particle physics context, this 17th Paris Colloquium 2013 is devoted to the LambdaWDM Standard Model of the Universe.

This Colloquium is within the astrofundamental physics spirit of the Chalonge School, focalised on recent observational and theoretical progress in the CMB, dark matter, dark energy, the new WDM framework to galaxy formation, and the theory of the early universe inflation with predictive power in the context of the LambdaWDM Standard Model of the Universe. The Colloquium addresses as well the theory and experimental search for the WDM particle physics candidates (keV sterile neutrinos). Astrophysical constraints including sterile neutrino decays points the sterile neutrino mass m around 2 keV. WDM predictions for EUCLID and PLANCK start to be available. MARE and an adapted KATRIN experiment could detect a keV sterile neutrino. A formidable WDM work to perform is ahead of us. In summary, the aim of the meeting is to put together real data : cosmological, astrophysical, particle, nuclear physics data, and hard theory predictive approach connected to them in the framework of the LambdaWDM Standard Model of the Universe.

Context, CDM crisis and the CDM decline: On large cosmological scales, CDM agrees in general with observations but CDM does not agree with observations on galaxy scales and small scales. Over most of twenty years, increasing number of cyclic arguments and ad-hoc mechanisms or recipes were-and continue to be- introduced in the CDM galaxy scale simulations, in trying to deal with the CDM small scale crisis: Cusped profiles and overabundance of substructures are predicted by CDM. Too many satellites are predicted by CDM simulations while cored profiles and no such overabundant substructures are seen by astronomical observations. Galaxy formation within CDM is increasingly confusing and in despite of the proposed cures, does not agree with galaxy observations. On the CDM particle physics side, the situation is no less critical: So far, all the dedicated experimental searches after most of twenty years to find the theoretically proposed CDM particle candidate (WIMP) have failed. The CDM indirect searches (invoking CDM annihilation) to explain cosmic ray positron excesses, are in crisis as well, as wimp annihilation models are plagued with growing tailoring or fine tuning, and in any case, such cosmic rays excesses are well explained and reproduced by natural astrophysical process and sources. The so-called and repeatedly invoked ‘wimp miracle’ is nothing but being able to solve one equation with three unknowns (mass, decoupling temperature, and annihilation cross section) within wimp models theoretically motivated by SUSY model building twenty years ago (at that time those models were fashionable and believed for many proposals). After more than twenty years -and as often in big-sized science-, CDM research has by now its own internal inertia: growing CDM galactic simulations involves large super-computers and large number of people working with, without agreement with the observations ; CDM particle wimp search involve large and long-time planned experiments, huge number of people, (and huge budgets) without producing wimp detection; one should not be surprised in principle, if a fast strategic change would not yet operate in the CDM and wimp research, although its interest would progressively decline.


  • Observational and theoretical progress on the nature of dark matter : keV scale warm dark matter
  • Cored density profiles in agreement with observations.
  • Large and small scale structure formation in agreement with observations at large scales and small (galactic) scales.
  • Warm (keV scale) dark matter from theory and observations.
  • The new quantum mechanical framework to galactic structure. WDM core sizes in agreement with observations.
  • Supermassive Black Holes : Theory and Observations. The clarifing and unifying WDM framework for stars, galaxies and cosmology.
  • Warm (keV scale) dark matter N-body simulations in agreement with observations.
  • Neutrinos in astrophysics and cosmology.
  • The new serious dark matter candidate: Sterile neutrinos at the keV scale.
  • Neutrinos mass bounds from cosmological data and from high precision beta decay experiments.
  • Dark energy: cosmological constant: the quantum energy of the cosmological vacuum.
  • The analysis of the CMB+LSS+SN data with the effective (Ginsburg-Landau) effective theory of inflation: New Inflation (double well inflaton potential) strongly favored by the CMB + LSS + SN data.
  • The presence of the lower bound for the primordial gravitons (non vanishing tensor to scalar ratio r) with the present CMB+LSS+SN data.
  • CMB news and polarization. Forecasts and Planck results.