1. Bose-Einstein Condesates as Galactic Dark Matter Halos Tonatiuh Matos, F. Siddhartha Guzman, Luis Ureña, Dario Nuñez, Argelia Bernal. http:/www.fis.cinvestav.mx/~tmatos Inflation +  CDM Model = Cosmology Galaxies Formation

2. Problems with the  CDM Model Dark Energy: Extreme fine tuning for  Coincidence Dark Matter: Cuspy central density profiles Too much substructure Too late galaxy formation Too early metalicity formation Etc.

3. The Model Examples: Braneword Scenario Superstrings  V  f 1 exp(  ) + f 2 exp(-  ) + … V = V 0 [cosh(  ) – 1] H 2 = 8  /(3M pl 2 )  (1 +  / b )  Inflation  graceful exit  BBN  Cosmology  Fix the free constants.

4. The Cosmology T. Matos and L. Ureña, Class. Q. Grav. 17(2000)L75 Dark Matter:  V 0 [cosh(  ) –1] Dark Energy:   Baryons, Neutrinos, etc.    0.25    0.7  b  0.05

5. Scalar Field Fluctuations T. Matos and L. Ureña, Phys. Rev. D63(2001)063506

6. Natural Cut-off

7. Summarizing SFDM model is insensitive to initial conditions Behaves as CDM 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 V 0  (3  10 -27 M pl ) 4  m   10 -23 eV

8. Scalar Field Fluctuation = Halo Tonatiuh Matos and F. Siddhartha Guzman Class. Q. Grav. 17(2000)L9; Tonatiuh Matos, F. Siddhartha Guzman and Dario Nuñez, Phys. Rev. D62(2000)061301(R); Tonatiuh Matos and F. Siddhartha Guzman, Class.Q. Grav. 18(2001)5055 M  0.1 M 2 Planck /m  If m m  10 -23 eV M  10 12 Mo

9. Scalar Field Fluctuation = Halo Tonatiuh Matos and F. Siddhartha Guzman Class. Q. Grav. 17(2000)L9; Tonatiuh Matos, F. Siddhartha Guzman and Dario Nuñez, Phys. Rev. D62(2000)061301(R); Tonatiuh Matos and F. Siddhartha Guzman, Class.Q. Grav. 18(2001)5055

11. Density Profiles

13. LSB Galaxies

14. Conclusion The scalar field is a good candidate to be the Dark Matter of the Universe