Ecole Internationale Daniel Chalong

Chalonge Meudon Workshop 2013


CIAS Observatoire de Paris, Château de Meudon, Meudon campus

5, 6 and 7 June 2013

Programme and Time Table (.pdf)

Practical informations (.pdf)

Click to download the poster (.jpg)

Programme and Lectures (.pdf)

List of Registered Participants (.pdf)

Album Photos


1. Summary: A Turning Point operated recently in the Dark Matter research: Warm Dark Matter (WDM) emerged impressively over Cold Dark Matter (CDM) as the leading Dark Matter candidate. WDM solves naturally the problems of CDM and agrees with the observations at small as well as large and cosmological scales. This workshop addresses the last developpements in WDM, including the new quantum mechanical framework to galaxy structure reproducing in particular the observed galaxy cores and their sizes. The workshop puts together astrophysical, cosmological and particle WDM, astronomical observations, theory and WDM computational analytical and numerical frameworks which reproduce the observations. The Workshop addresses as well the experimental search for the WDM particle candidates (keV sterile neutrinos).

2. The New Dark Matter Situation Today: Warm Dark Matter (WDM) research is progressing fast, the subject is new and WDM essentially works, naturally reproducing the astronomical observations over all scales: small (galactic) and large (cosmological) scales (LambdaWDM). Astronomical evidence that Cold Dark Matter (LambdaCDM) and its proposed tailored cures do not work at small scales is staggering. Astrophysical constraints including sterile neutrino decays points the sterile neutrino mass m around 2 keV. WDM predictions for EUCLID and PLANCK start to to be available. MARE and an adapted KATRIN experiment could detect a keV sterile neutrino. It will be a fantastic discovery to detect dark matter in a beta decay. A formidable WDM work to perform is ahead of us.

3. History, Context and the CDM crisis: This Workshop is the fourth of a new Chalonge series in Meudon dedicated to Dark Matter. The first Workshop of this series (June 2010) allowed to identify and understand the issues of the serious problems faced by Cold Dark Matter (CDM) to reproduce the galactic (and even cluster of galaxies) observations. The 2010 and 2011 Workshops served as well to verify and better understand the confusion in the CDM research, namely the increasing number of cyclic arguments, and ad-hoc mechanisms introduced in the CDM simulations over most of twenty years, in trying to deal with the CDM small scale crisis: Cusped profiles and overabundance of substructures (too many satellites) are predicted by CDM. In contrast, cored profiles and no such overabundant substructures are seen by astronomical observations. The too many galaxy formation and evolution CDM models are plagued with ever increasing tailoring or fine tuning.

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 repeatedealy 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 without reproducing the astronomical observations : growing CDM galaxy simulations involve large super-computers and large number of people working with; CDM particle wimp search involve large and long-time planned experiments, huge number of people, (and huge budgets); one should not be surprised at all, if a fast strategic change would not yet operate in the CDM computer (and super-computer) simulations and wimp research, although its interest would progressively decline.

4. The Workshop addresses the last and fast progresses made in Warm Dark Matter Galaxies in Agreement with Observations. In the tradition of the Chalonge School, an effort of clarification and synthesis will be made by combining in a conceptual framework, theory, analytical, observational and numerical simulation results. The subject will be approached in a threefold way:

(I) Conceptual context: Dark Matter in cosmology and astrophysics: perspective and prospective of the research in the subject: Theory and observations. The emergence of Warm (keV scale) Dark Matter from theory and observations.

(II) Astronomical observations : galaxy structural properties, the universal and non universal properties of galaxies, high quality rotation curves, kinematics, density profiles, gravitational lensing, small and large structures, deep surveys, clusters of galaxies

(III) Computational framework with the equations of physics. Analytical and numerical frameworks. The new important physical ingredient in galaxy structure: quantum mechanics. Classical (non quantum) numerical simulations with Warm Dark Matter and resulting structures. Results versus observations.

Special attention will be payed to the astrophysical understanding of the dark matter problems and its solution, the use of analytic and numerical methods which determine the properties, the density profiles, masses, sizes and evolution, the distribution and the nature of Warm Dark Matter.


Kinetic theory and the recent progress in solving the Boltzmann-Vlasov equation to obtain the observed universal properties of galaxies. N-body numerical simulations whith Warm dark Matter.

The phase-space density of dark matter.

Particle model independent analysis of astrophysical dark matter.

The impact of the mass of the dark matter particle on the small scale structure formation and the choice of the initial conditions.

The radial profiles and the Dark Matter distribution. Observed galactic cored profiles

The keV scale Dark Matter (Warm Dark Matter): Observational and theoretical progresses.

The new quantum mechanical framework to galactic structure. WDM core sizes in agreement with observations.

Large and small scale structure formation in agreement with observations at small galactic and at large scales.

The new serious dark matter candidate: Sterile neutrinos at the keV scale

Supermassive Black Holes : Theory and Observations. The clarifing and unifying WDM framework for stars, galaxies and cosmology.



All Lectures are followed by a discussion. All participants are invited to take part in the discussions.

Enough time will be available for the discussions.

The Meeting is open to all scientists interested in the subject. Registration is mandatory. Registration information is given below.

The format of the Meeting is intended to allow easy and fruitful mutual contact and communication.

Sessions last for three full days in the beautiful and green Meudon campus of Observatoire de Paris in the historic Castle with the Great Dome building ("Château Grande Coupole") where CIAS (Centre International d´ Ateliers Scientifiques) is located.

All lectures and presentations will take place at the Castle Conference Room (Salle de Conferences du Château) in the historic Castle building.

All Coffee-Tea breaks will take place at the Urania Hall aside the castle conference room in the same building. The Registration desk and the Secretariat of the Workshop take place at the Urania Hall.

Discussions and working sessions all during the workshop will take place at the CIAS rooms aside the Urania Hall.

SOC et LOC :

Norma G.Sanchez, Hector J. de Vega, Peter Biermann, Maria Cristina Falvella

Nicole Letourneur, Dominique Lopes, Sylvain Cnudde, Emmanuel Vergnaud, Djilali Zidani


Peter BIERMANN (MPI-Bonn, Germany & Univ of Alabama, Tuscaloosa, USA)
Warm Dark Matter and astrophysical signatures.

Jacques DELABROUILLE (APC, Paris, France)
Planck Cosmological Results and their implications

Hector J. DE VEGA (CNRS LPTHE Univ de Paris VI, France)
Fermionic Warm Dark Matter reproduces galaxy observations because of quantum mechanics

Wyn EVANS(Institute of Astronomy, Cambridge, UK)
The Structure of Dwarf Galaxies

Ayuki KAMADA (IPMU Inst. Physics & Mathematics of the Universe, Univ of Tokyo, Japan)
Dark Matter Halos in Warm Dark Matter Models.

Andrea LAPI (Università Roma2, Rome, Italy)
The Statistics of Warm Dark Matter Halos from the Excursion set approach.

Thierry LASSERRE (CEA, IRFU-Saclay, France)
Status report on active and sterile neutrino experiments.

Elena FERRI & MARE Experiment (Milano Biccoca, Italy)
Status of MARE for the keV sterile neutrino detection.

Alessandro MELCHIORRI(Univ. Roma 1 La Sapienza,Italy)
Planck Results for neutrinos and their implications

Alexander MERLE (Physics and Astronomy, University of Southampton Highfield Southampton UK)
Particle physics models for keV Sterile Neutrino Dark Matter

Susanne MERTENS (Inst. for Nuclear & Particle Astrophysics, LBNL Berkeley, CA, USA)
Warm Dark Matter searches with Tritium Beta Decay experiments.

Sinziana PADOROIU (Observatoire de Geneve, Switzerland)
Small scale structure from WDM N-body Simulations

Brigitte ROCCA-VOLMERANGE (Univ Paris-Sud & IAP, Paris, France)
Observations of the most distant radio galaxies and their implications

Paolo SALUCCI (SISSA-Astrophysics, Trieste, Italy)
Testing Warm Dark Matter with Galaxy observations at high redshifts

Norma G. SANCHEZ (CNRS LERMA Observatoire de Paris, Paris, France)
Quantum Fermionic Warm Dark Matter and Gravitation: Galaxies in Agreement with Observations and Supermassive Black Holes. New Results

Aurel SCHNEIDER (Dept of Physics & Astronomy, Univ of Sussex, Falmer, Brighton, UK)
Constructing Warm Dark Matter mass functions

Nicholas STEINBRINK (Institut für Kernphysik Westfälische Wilhems-Universität Münster, Germany)
Neutrino Mass Measurements and Sterile Neutrino Detection at KATRIN

Ignacio TRUJILLO (Instituto de Astrofisica de Canarias La Laguna, Tenerife , Spain)
Structural evolution of Galaxies since z ~ 2, size and mass evolution from Astronomical Observations.



Local and practical information can be found below.


The Meeting is open to all scientists interested in the subject but Registration is mandatory. Registration fee is 60 Euros. The registration fee covers the 6 coffee-tea breaks, the tickets for the 3 lunchs and the cocktail/reception. The registration fee must be paid cash to the Secretary of the Workshop (not by credit card, nor by check) at the registration desk on the 1st day of the Workshop (Wednesday 5 June 2013).
[The Lunch tickets you will receive at the Workshop Registration include for Each Lunch at the Observatory self-restaurant in Meudon the following six items: Entry/appetizer. Main course. French cheese or green salad. Dessert (cakes or fruits or yoghurt). Drink (wine, beer or mineral water or other soft drinks). Coffee or Tea . For Each item a variety of choices is proposed every day (meat, fish, chicken, vegetarian, with their garnitures). Also, one can skip one item and have instead another item twice].

Certificates of participation and receipts will be delivered by the Secretariat during the Workshop upon request.

Participants wishing to attend the Meeting should register in time, by on line registration (on the top of this page)and in any case           

BEFORE 1st MAY 2013

An automatic mail  is sent to you after your on line registration.

Some selected presentations or posters on WDM from registred participants will be included in the workshop programme


The LIST of Registered confirmed Participants will be posted in May.  BADGES for all registered confirmed participants in the list will be available at the Registration desk from Wednesday 5 June at 8:10 am.

Please wear your badge all during the Workshop, which will make easy your access and circulation within the Paris Observatory Meudon campus.


Workshop Secretariat:

We look  forward to seeing you in Meudon for a creative, fruitful and enjoying meeting.

Participants should make their reservations by their own. A list of hotels in Paris nearby Montparnasse station is provided below.


Welcome of the participants and Registration starts on wednesday 5 June at 8:00 am at the Urania Hall in the historic Meudon Castle ("Château de Meudon"). Tickets for lunch will be on sale at the registration desk from Tuesday morning.

Lectures start on Wednesday 5 JUNE at 8:00 am in the Castle ("Chateau") CIAS building .

We shall  strictly stick to the timetable during the whole meeting.

All lectures and events will start  at the indicated times sharp.

All sessions take place in the historic Castle ("Château" building) where CIAS is located ,

All COFFEE-TEA-MATE-CHAMPAGNE BREAKS take place in the Urania Hall in the CIAS Château building.

LUNCH is served at the Self-service Restaurant of Observatoire de Paris at Meudon (located very near from the "Château" building, inside the Meudon campus, around the pond).

The PHOTO of the group will be taken in the middle of one of the main entries of the "Chateau".

The COCKTAIL/RECEPTION for all participants and accompanying persons will be offered on FRIDAY 7 JUNE in the late afternoon at the terrasse (if weather allows it) aside Urania Hall; otherwise, inside the Castle.

Please Notice: The Workshop ends after the COCKTAIL/RECEPTION in the late afternoon of Friday 7 June. All participants and lecturers are expected to stay untill the end of the Meeting.

LOCATION : The entrance of the Observatoire de Paris at Meudon is 5, Place Jules Janssen, F-92 190 Meudon (see below how to reach Meudon).

Lunch is served at the Self-service Restaurant of Observatoire at Meudon (located very near from CIAS Castle, inside the Meudon campus, around the pond). The tickets for lunch will be available at the Conference registration desk from Thursday morning.

On Friday, there will be a Cocktail/Reception in the the late afternoon in the Urania Hall/terrasse. The Observatoire Self-Service Restaurant is closed for dinner and on Saturdays /Sundays.

Some Restaurants are listed below.


Address : 5, Place Jules Janssen, F-92 190 Meudon .Tel: .Fax:

 Longitude : 2° 14' East . Latitude : 48° 48' North . Altitude : 162m

Meudon Observatory is located Place Jules Janssen , in Meudon at the top of the Avenue du Château.

By train. The best way for visitors to reach Meudon Observatory is from Paris-Montparnasse train station and to stop at Bellevue station (recommended stop). The travel duration by train from Paris Montparnasse to Bellevue station is about 12 minutes. Recommended way is the following:

By train (French railways - SNCF): At Paris-Montparnasse station, take the train going to Sèvres or to Versailles-Chantiers, Rambouillet, Chartres, (which frequency is every 15 min.). Make sure that the train stops at the Meudon or Bellevue stations. Get out at the 4th station: Bellevue (after Vanves-Malakoff, Clamart and Meudon stations).

Once outside Bellevue station, turn left (passing the church aside the station) and take the green Avenue du Château bordered by trees: the entrance of the Observatory is on the top of the hill. About a 10/15 minutes walk to reach the gates of the Observatory. [There is also a mini bus (circular local line) from the Bellevue station to the Observatory].

If you stop at the Meudon station: outside the station, turn to the right, after 200 m turn again to the right to take avenue Corbeiller [where the Meudon Municipality is located (Mairie de Meudon), ahead up to the top of the hill along avenue Corbeiller, rue Jacqueminot lined with stately chestnut trees.

Once arrived, use the map of the Observatory campus: Chateau Grande Coupole CIAS where the meeting takes place, (building 9 in the map) is on the terrasse (take the staircase in the garden at the left after the entry and then at the left straight on the road along the terrasse bordered by the chestnut trees.

By car there are 2 possible routes : Take the périphérique, exit at Quai d Issy, then go towards Issy les Moulineaux, Sèvres and finally Meudon Take N 118, from the Pont de Sèvres, going towards Chartres Orléans, exiting at Meudon Sèvres and then going towards Meudon.


Hôtel du Maine; 16 Rue Maison Dieu, Paris, 75014

Hôtel Ibis; 71 boulevard de Vaugirard, Paris, 75015

Hôtel Montparnasse-Daguerre; 94 rue Daguerre, Paris, 75014

Hôtel Campanile - Maine Montparnasse; 146 Avenue du Maine, Paris, 75014

Hotel l'Aiglon, 232 boulevard Raspail, metro Raspail, tel. 33 (0) 143208242,

Hotel Delambre 35 rue Delambre, metro Edgar Quinet, tel. 33 (0) 145389176,

Hotel de la Paix, 225 boulevard Raspail, metro Raspail,tel. 33 (0) 143353263,

Mercure Raspail Montparnasse, 207 bd Raspail, Paris 75014 .Tel.33 (0). 14320-6294, fax 33(0).14327-3969.

Hotel du Midi, 4, Av. René Coty, Paris 75014. Metro : Denfert-Rochereau. tel. 33(0).14327-2325. fax 33(0).14321-2458.

FIAP Jean Monnet, 30 rue Cabanis, 75014 Paris
Metro Glaciere or Saint-Jacques

Tel. 33(0)1-4313-1700. Fax 33(0)1-4581-6391.


La Closerie des Lilas, 171, boulevard Montparnasse. Tel. 014051-3450.Open everyday till 1 am.

Formerly a Café littéraire had as customers Baudelaire, Verlaine, Gide, Jarry, Apollinaire, Modigliani, Hemingway, Lenin and probably Trotsky. Keeps a litterary crowd of customers like Philippe Sollers. The present chef Jean-Pierre Cassagne has renovated the house and the excellent meals. Besides the restaurant there is `brasserie' where meals are alsoserved. Menu 43 euros (including wine), à la carte 90 euros.

La Rotonde Montparnasse, 105 bd. Montparnasse, Tel. 0143266884. Open every day from 12 am till 1pm. Typical parisian restaurant since 1911.  Seafood, oysters, famous Salers entrecote, good fish, selected Auvergne cheese and good desserts. Landmark of the Montparnasse district had as regular customers artists, musicians, writers and politicians: Modigliani, Picasso, Soutine, Cocteau, Diaghilev, Debussy, Nijinski, Stravinsky, Man Ray (and Kiki), Breton, Aragon, Prevert, Queneau, Hemingway, Gershwin, Henry Miller, Scott Fitzgerald. Meetings of Trotsky with fellow bolcheviks in the first floor room to organize the 1917 russian revolution were often interrupted by the french police. Menus 35 and 43 euros.

La Coupole, 102 bd. Montparnasse, Tel. 0143201420.   Open every day from 12 am till 1 pm.

Typical Art Deco parisian restaurant open in 1927. Seafood, salmon rilletes, abundant sauerkraut, fresh codfish a la plancha, entrecote with french frites, lamb curry india style, excellent desserts. Among regular customers in the past: Cocteau, Prevert, Sartre, Beauvoir, Picasso (who met here Dora Maar), Matisse, Piaf, Montand.



At present the Observatoire de Paris owns three campuses: Paris, Meudon and the radioastronomy station at Nançay. More than 700 scientists, technicians and administrative staff work there.

The history of the present Meudon Castle (Château de Meudon) starts several centuries ago.

The new Château de Meudon over where the cupola of the Meudon Observatory is installed was built in 1706 by the great architect Jules-Hardouin Mansart in orders by King Louis XIV for his son the Grand Dauphin. This was the last important project realized by Mansart. The gardens and water fontaines were constructed under the plans by Le Nôtre. Important visitors stayed in the Château de Meudon in the XVIII century as the Zar of Russia Peter the Great and the King of Poland Stanislas Leszczyski.

After the French Revolution, a workshop to construct military balloons was settled in the area. These balloons played an important rôle in the Fleurus battle against Austria in 1794. Napoleon restaured the Château de Meudon and the Empress Marie-Louise and their son (the King of Rome) lived in the Castle.

The terrasse was used by the prussians to shell Paris during the siege of 1870. The Château de Meudon took fire at that time.

In 1876 the astronomer Jules Janssen created the Meudon Observatory and in 1893 a refraction telescope was installed over in the Castle.



Museums at Meudon

Musée - Atelier Rodin , Villa des Brillants Beaux-Arts. House-workshop and garden of the artist. Original casts of the work of the great sculptor. The Tomb of the sculptor with one his versions of the "The Thinker".

Musée d'Art et d'Histoire de la Ville de Meudon Beaux-Arts - Histoire

Fondation Arp à Clamart 1.8 km (sud-est limit of the Meudon forest). House-workshop and garden of the artists Jean Arp and Sophie Taeuber who designed the house in 1960. Epured Cubism. Abstraction and Dadaisme. Kandinsky "Blaue Reiter"mouvement of 1912. Max Ernst, Tristan Tzara, Constructivist Théo Van Doesburg. Original and asttonishing constructions in the "Triangle des Châtaigniers" (Chestnuts Triangle) designed by Chemetov, Déroche and Lecaron architects.


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