Refining the free function of MOND Workshop Program Dark Matter and Alternative Gravities

Day 1: Galaxies and Solar System Day 2: Large Scale and Lensing Day 3: Satellites and Challenges for all theories

Day 1: Galaxies The acceleration discrepancy problem Large halos of DM CDM: Large Scale Structure and best candidate

Is the missing satellite problem solved? How do we solve the cusp problem in CDM? Is WDM the solution? (cf. e.g. dSph) What about the  -WDM cosmological model? Wiggles of the rotation curves?

ggWith DM, how do we explain the « order » encapsulated in the well-known MOND formula?  (  g  /a 0 ) g = g N baryons with  (x) = x for x « 1 (MONDian regime)  (x) = 1 for x »1 (Newtonian regime) Is this going to end as an equivalent of Titus Bode’s law for the solar system? If not, could it be the signature of exotic DM somehow interacting with baryons? Are there candidates?

Day 1: Solar System Pioneer anomaly: end of gravity as we know it? Thermal emission anisotropy of the spacecraft? Is acceleration different for different orbits? => Modified Inertia? End of « metric » gravity?

Day 2: Large Scale Are massive galaxies at very high redshift a challenge to standard hierarchical model? CMB anisotropies: the most serious challenge to any modified gravity theory? Galaxy clusters: failure of the MOND formula + lensing of interacting clusters : => surviving « hybrid » theory? (e.g. BSTV)

Dark Energy: do we know enough about supernovae? (models don’t explode, while they are the only direct evidence) Isn’t there too much dark energy in a flat TeVeS Universe, in order to fit supernovae? Running cosmological constant? Non-MOND modifications of the left-hand side of Einstein equation? Is unification with DM possible?

Day 2: Lensing Is the scatter observed in the lenses gravity vs. lenses baryonic content real, or due to too many uncertainties in the analysis? If confirmed, this scatter cannot be fitted by any modified gravity theory What about lensing in conformal gravity?

Day 3: Galactic Satellites MOND: Dwarf spheroidals need DM if their size is primarily determined by tides, as distant globular clusters are Not all internal velocity dispersion profiles of dSph are compatible with the MOND formula (bigger problem than in galaxy clusters)

Day 3: Challenges DM: cusps DM: wiggles of RC’s MOND: CMB, galaxy clusters,  function (precise M/L could fix  and rule TeVeS out) E.g. in conformal gravity, how do we handle complex geometries? What happens to dynamical friction in any modified gravity theory? Can a hybrid theory save e.g. the issue for dSph? ETC.