Oscillatons as Galactic Dark Matter Halos

Tonatiuh Matoshttp:/www.fis.cinvestav.mx/~tmatos

• Inflation• +• Scalar Field DM

(SFDM)• +• Dark Energy

Cosmology +Galaxies Formation

=

• The model consists of

THE SCALAR FIELD DARK MATTER MODEL

• It is an alternative model to CDM• SFDM model is insensitive to initial conditions • Behaves as CDM at cosmological scales• Reproduces all the successes CDM above

galactic scales.• Predicts a sharp cut-off in the mass power

spectrum • The favored values for the two free parameters 20 V0 (310-27 Mpl )4 m 10-23 eV

The Model comes from• Examples:• Braneword Scenario• Superstrings • contain effective SF potentials:• V f1exp() + f2exp(-) + …• • V = V0[cosh() – 1]

• If• H2 = 8/(3Mpl

2) (1 + /b)• Inflation graceful exit• BBN Cosmology • Fix the free constants. • James Lidsey, Tonatiuh Matos and Luis A.

Ureña. PhysRevD66(2002)023514.

The CosmologyT. Matos and L. Ureña, Class. Q. Grav. 17(2000)L75

• SFDM with the SF potential:• V = V0[cosh() –1]• Dark Energy:

• +

• Baryons, Neutrinos, etc.

0.23 0.73b 0.04

Scalar Field Fluctuations

T. Matos and L. Ureña, Phys. Rev. D63(2001)063506

The linear fluctuations of the SFDM model follow the

CDM ones

Natural Cut-off

The linear fluctuations contain a natural cut-of in the mass power spectrum. Thus, this model has no problems with

the production of substructure.

Scalar Field Fluctuation = Oscillaton = Galaxy Halo

Tonatiuh Matos and F. Siddhartha Guzman Class. Q. Grav. 17(2000)L9; T. Matos, F. S. Guzman and D. Nuñez, Phys. Rev. D62(2000)061301(R);Tonatiuh Matos and F. Siddhartha Guzman, Class.Q. Grav. 18(2001)5055

The critical mass of oscillatons collapse is

• Mcrit 0.1 M2Planck /m

• If m 10-23 eV 20

• Mcrit 1012 M¯ ~ Galaxy halo

Galaxy virialization

• The oscillatons virialize in a very short time. In this figure it is shown the rate of kinetic energy K and potential energy |W| of the scalar field fluctuation. It goes very fast to ½.

Density Profiles

Here we show the comparison between the NFW, Isothemal and the SFDM density

profiles for galaxies.

Density Profiles

Density Profiles

LSB Galaxies

Density Profiles

LSB Galaxies

Conclusion

• The scalar field is a good candidate to be the Dark Matter

of the Universe