Archivi tag: CMB

Warm Dark Matter Cosmology in agreement with observations

Warm Dark Matter (WDM) is hot topic in galaxies cosmology and implies novelties in the astrophysical, cosmological particle and nuclear physics context. Warm Dark Matter Cosmology (LWDM) gives the same successfull large scale results and CMB results than Cold Dark Matter (LCDM) and succesfully agrees with the observations at the galactic and small scales. 

Continua a leggere Warm Dark Matter Cosmology in agreement with observations


Statistical Challenges in 21° Century Cosmology

In the era of large astronomical surveys that are grappling with unsolved methodological and data challenges, transforming Data into Science is a huge, and exciting, problem. With surveys and instruments such as Planck, Pan-STARRS1, DES, VST KiDS, LSST, Gaia, EUCLID, JPAS, SKA, wide-field spectroscopic surveys and the large and interconnected databases of archival material coming online, a special scientific focus on cosmological inference is of great interest. Without this focus there is no guarantee that the best possible Science will be the outcome of this data-flood. But transforming data into knowledge is still a largely unsolved problem; a problem, that must be tackled by cross-disciplinary efforts.

Continua a leggere Statistical Challenges in 21° Century Cosmology

Rencontres de Moriond on Cosmology

The Rencontres de Moriond session on Cosmology will review the subject 2 years after the last edition.

The main topics of the conference are:

  • CMB anisotropies
  • Reionization
  • Dark energy probes
  • Dark Matter
  • Inflation
  • Modified gravity
  • Massive gravity
  • Galaxy clusters
  • SZ
  • Non gaussianities

The conference will include both review and contributed talks and will be organized only in plenary sessions

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.

Exploring the physics of inflation

The year 2013 will be exciting and full of new results based on the measurement and analysis of CMB temperature fluctuations, polarization, and LSS data. The Planck satellite is expected to provide new cosmological information and release all-sky CMB maps with unprecedented quality in the early part of 2013. These new results, along with the information that will be produced by on-going and planned CMB and LSS experiments will be a very important contribution to improving our knowledge on the inflationary period of the universe. The meeting will focus on the physics of inflation from an observational, theoretical, and instrumental perspective. Special emphasis will be given to results derived from the forthcoming polarization data. The conference takes place in the context of the Spanish Consolider-Ingenio Project known as EPI: Exploring the Physics of Inflation. There will be a limited number of invited talks in order to allow the majority of the time for contributed discussion. The conference will be in Santander, which is located on the northern coast of Spain. Santander is a popular summer destination surrounded by some of the most popular beaches in the north coast. The dates of the conference were chosen to avoid the peak of the tourist season, in order to offer a more relaxing (and affordable) environment.

Cosmic Microwave Background 2013

Detection of primordial gravitational waves would be one of the most significant scientific discoveries of all time. Such a detection would be a direct evidence for inflation and shed light on fundamental physics such as quantum gravity behind inflation. The accurate measurement of CMB polarization is the best way to discover the primordial gravitational waves. It is thus one of the greatest challenges in experimental cosmology in the next decade. Thanks to remarkable technological development in recent years, the detection is not a mere dream anymore but becoming factual. The primary objective of the conference is to exchange ideas on how to reach the precision at the level of r=0.001 or even better, where r is the tensor-to-scalar ratio. Another important goal of the conference is to evaluate scientific values of such a measurement, where relations to other observations such as CMB temperature anisotropies are also important. To these ends, the conference will have talks from all the CMB projects in operation, in preparation or in planning.

The conference consists of plenary sessions and poster sessions. Topics in the plenary sessions will include the following:

– Planck results/instruments
– On-going ground/balloon CMB experiments
– CMB experiments in preparation
– Future CMB experiments including satellites
– Theory overviews
– Nature of foregrounds and their separation

Talks in the plenary sessions are by invitation only. Poster sessions will be based on abstract submissions to cover a broad range of topics on CMB research, from inflationary model building to superconducting sensor development, which will stimulate vigorous and open discussions among participants. Posters on a wider range of topics related to CMB are also welcomed; examples of such topics are:

– Synergy between CMB and other observations, such as CIRB, 21cm, dark energy and dark matter.
– Astrophysics/astronomy with foregrounds.

Reconstructing the Universe: A Celebration of Alexei Starobinsky @ 65, IEU @ 5, and New Research

“Reconstructing the Universe” is an international cosmology research conference with three foci:

  • Research topics contributed to by Prof. Alexei A. Starobinsky, on the occasion of his 65th birthday
  • Research projects of the IEU during its first 5 years
  • New results in cosmology

Starobinsky Fest

  • Alexei Starobinsky (Landau ITP) — Inflationary Models Most Favoured by the Planck and Other Recent Observational Data
  • Alexander Kamenshchik (INFN Bologna) — Scalar Fields in Classical and Quantum Cosmology
  • David Polarski (Montpellier) — Dark Energy: a New Vision at Our Universe
  • Misao Sasaki (Yukawa ITP) — Violating Non-Gaussianity Consistency Relation in Single Field Inflation
  • Arman Shafieloo (APCTP) — Falsifying Cosmological Constant

IEU Fest

  • Yipeng Jing (Shanghai) — Probing Dark Energy with Information of Non-linear Redshift Distortion
  • Eric Linder (IEU/Berkeley) — Cosmological Constraints from Large Scale Structure
  • Hitoshi Murayama (Kavli IPMU)
  • Il Park (Sungkyunkwan) — Simultaneous Observation of UV/optical and X-rays from Gamma Ray Bursts and its Physical Importance
  • Uros Seljak (IEU/Berkeley) — Theoretical Challenges in Large Scale Structure
  • Jongmann Yang (IEU) — Results on High Energy Cosmic Ray Experiments

New Research Fest

  • Pisin Chen (LeCosPA) — Inflation as a Solution to the Early Universe Entropy Problem
  • Olivier Dore (JPL) — Planck 2013 Cosmology Results
  • Masashi Hazumi (KEK) — Current and Future CMB Polarization Measurements
  • Neal Katz (UMass) — The Ins and Outs of Galaxy Formation
  • Masahiro Takada (Kavli IPMU) — Can We Use Galaxy Clustering for Precision Cosmology? – Connecting Galaxies and Dark Matter Halos
  • Mark Trodden (Penn) — Results on Galileons and Massive Gravity

More details here.

Exploiting the Herschel and Planck data

The Doctoral School of Astronomy-Astrophysics of Paris Area (ED 127) is the only thematic doctoral school in France, in the field of astronomy and astrophysics. The school is supported by four universities or Institutes : the Paris Observatory (carrier), Université Paris-Sud (P11), Université Paris Diderot (P7) and UPMC (P6).

Since 2008, the Doctoral School organizes a biennial international school in the field of observational astronomy, intended for PhD students and postdocs. The third edition of this school will be held in March 2013. The previous two had been very successful and received about 40 participants each, representing more than fifteen different nationalities. This is the third edition of a school with the goal to train young researchers, PhD students and postdocs, regardless of nationality, to the scientific exploitation of two recently launched European space missions, Planck and Herschel. The first results obtained by these two satellites, the most successful ever launched in their respective fields, are reshaping the landscape in many areas of astrophysics (cosmology, galaxies and large structures, star formation, interstellar medium, the solar system) and there is some urgency to introduce the concepts and specific methods of exploitation of their data to future researchers. The school last one week and will follow the organization of the two schools previously held by the ED 127, a scheme that has proved itself and was appreciated by participants. The morning is devoted to lectures given by leading researchers, from around the world, and the afternoon is devoted to practical work in pairs around computers. These includes manipulating data from each satellite, a familiarization with the software to access, treatment and data analysis, using tools developed by space agencies and consortia of the two scientific missions. The astrophysical interpretation will also be addressed by numerical models developed by the community. We will offer to students the opportunity to explore the complete chain that goes from theory to the analysis of astrophysical observations. From a practical standpoint, the whole school will be held at the International Centre of Pedagogical Studies (CIEP) in Sèvres, a center able to accommodate all participants in half-board at a reasonable cost and providing modern teaching facilities. The morning will be devoted to lectures and the afternoon, students will use the computer workstations in special rooms. Students will be invited to present a poster on a topic that motivates them particularly. A laboratory visit will take place during a half day. One feature of this school is to target a wide international audience, particularly to developing countries. Accordingly, we maintain a low registration fee, thanks to a call for funding by several partners.

More info: International Young Astronomer School on Exploiting the Herschel and Planck data