Astrophysical and Cosmological Impact of Extra Dimensions

1. Astrophysical and Cosmological Impact of Extra Dimensions

2. Focus on... Cosmological constraints on large extra dimensions (ADD) Universal extra dimensions as Dark Matter (UED)

4. homogeneous and isotropic • flat • big (low entropy) • scale invariant spectrum of perturbations • slight particle-antiparticle asymmetry • observed ratio of light elements • most of the universe is dark

6. R MF

8. Only Nucleosynthesis can be copied in the lab Due to weak interaction cuts off at T~MeV. Need to be in thermal equilibirum at this time.

9. Cosmological production of KK modes Each KK mode only gravitationally coupled to the standard model However, at an energy E there are many KK modes with m < E Emissivivity therefore goes like

10. Cosmological production of KK modes e.g. For photons.... And for electrons... Evolution of density Redshifts like matter MF and Griffiths hep-ph/0111435

11. Growth of perturbations Position of peak depends on total density of matter at z~5000 P~kn (n=1 from inflation?) Growth of structure suppressed on small scales

12. Constraints from Cosmological over-density of KK modes d=6 5 4 3 2 MF and Griffiths hep-ph/0111435

13. Compton Gamma Ray Observatory 1991-2000

14. Compton Gamma Ray Observatory COMPTEL Diffuse Background Radiation

15. Constraints from decay of KK modes into gamma rays Decay rate Lifetime... Constraints on MF :- Hall and Smith hep-ph/9904267 , Hannestad hep-ph/0102290

16. Supernova...

17. ...leaves behind a Neutron Star... ...and a halo of KK modes

18. Hannestad and Raffelt hep-ph/0110067

19. Chaotic Inflation in Large extra Dimensions Energy density has to be less than Fundamental scale For slow-roll, Inflaton mass must be less than H Leads to density perturbations of magnitude Obviously, simplest models cannot work Lyth hep-ph/9810320, Kaloper and Linde hep-ph/9811141

20. Hybrid Inflation in Large extra Dimensions Two field potential, inflaton field and waterfall field If we choose most reasonable parameters Difficult to understand without SUSY Lyth hep-ph/9810320, Kaloper and Linde hep-ph/9811141 Need to invoke some new mechanism

21. Possible Solution for Inflation with Large Extra Dimensions • Universe starts with extra dimensions small, close to • Newton’s constant • No problem to get large density perturbations • Extra dimensions then grow after inflation • Typically a problem with moduli field – requires extra phase of inflation Mazumdar hep-ph/9902381, Arkani-Hamed at al hep-ph/9903224

22. Effects of Low Reheat Temperatures • Changes relic abundance • Can make HDM particles like low mass axions CDM Giudice, Kolb and Riotto, hep-ph/0005123

23. Baryogenesis Sakharov’s three conditions need to be met:- C and CP violation B violation Out of equilibrium thermodynamics Condition 2 potentially met too easily in large extra dimension scenarios. (Proton decay) (neutron/anti-neutron mixing) Gradual reheating can make sphaleron processes viable with low thermalisation temperature (Riotto et al)

24. Dark Matter I have a good idea every two years. Give me a topic, I will give you the idea! Fritz Zwicky Coma Cluster 1933 velocity of galaxies in the cluster is too large for the visible mass of the cluster

25. Dark Matter: The Manyfold Universe Arkani-Hamed et al. hep-ph/9811386

26. Constraints on self interaction of dark matter

27. Constraints on self interaction of dark matter s < cm2 / g

28. Endpoint of black hole decay in string theory Black hole undergoes phase transition to string ball Bowick et al ’86, Amati et al ’89, Damour and Veneziano ‘99

30. Modified Unertainty Principle at Planck Scale ? Heuristic argument then suggests modified Hawking temperature :- Temperature goes to zero close to the Planck scale. Stable remnants at end point of black hole evaporation? Dark matter candidate? (Pisin Chen) N.B. This is not what string theory predicts…

31. Universal extra dimensions Appelquist et al. 2001 Extra dimensions of size R ~ 1 / TeV into which SM gauge fields propagate Simplest scenario is 1 extra dimension orbifolded Orbifolding leads to spectrum of Kaluza Klein (KK) modes such that the lightest KK mode is stable. Potential dark matter candidate (Servant and Tait 2002) Simplest models fully determined by

32. Mass spectrum of KK particles KK mass ~ 1/R + normal mass from higgs sector + radiative corrections, e.g. for higgs:- Cheng et al. 2006

33. Annihilation of LKKP into electrons is direct, unlike neutralinos Neutralino annihilation into electrons (goes via jets)

35. Chang et al. Nature 456, 362, 20th November 2008 ATIC AMS PPB

36. Can be interpreted as Dark matter Cut-off corresponding to 620 GeV KK particle However, need large boost factors, B = ( 10, 102, 103 ) for mDM = ( 100 GeV, 1 TeV, 10 TeV) respectively

37. Possible origins of the Boost Factor Thermally averaged self annihilation cross section today Actual local density Branching ratio into e+e- Expected local density (0.3 GeV cm-3) Thermally averaged self annihilation cross section at freeze-out

38. New H.E.S.S. data 0905.0105

39. New Fermi Data 0905.0025

41. Spitzer Infrared telescope 200 x 275 pc Very Large Array (radio)

42. 25 pc 280 pc Chandra X-ray observatory

43. 25 pc 10 pc

44. Sagittarius A* Mini spiral 1 pc

47. Mass contained within radius from stellar motions

48. Closest approach of SO-16 is 0.0002 pc =45 AU =600 Rsch 0.04 pc

49. Emission From Black Hole (best resolution at all frequencies)