Reheating the Universe after String Theory Inflations

1. Reheating the Universe afterString Theory Inflations PILJIN YINTU, 2005

2. Brane Inflation / Brane World: Prototype Dvali+Tye, 1998 Brane World /Standard Model +

3. String Theory Inflation (KKLMMT) Unstable D-Branes and Decay Products Reheating Hierarchical Brane Worlds Heavy Relic Problems

4. Content • Issues • Brane Inflation (KKLMMT) in a Nutshell • Unstable D-Brane Systems and Decay Products • Reheating • Summary and Outlook With Gibbons, Hori, Hashimoto, O-Kab Kwon hep-th/0009061, hep-th/0209034, hep-th/0305229 With Ho-Ung Yee, M. Gutperlehep-th/0402027, hep-th/0409050 With Lev Kofman hep-th/0507257

5. Usual Issues with Cosmology • Inflation Era: • Origin of Inflaton • Sufficient e-folding: Fine Tuning • Density Perturbation • Post-Inflation: • Reheating • Baryogenesis • Nucleosynthesis • Structure Formation and Dark Matter

6. Cosmology on Branes: mixing of closed string physics and open string physics • Inflation Era: • Simple Identification of Inflaton • Sufficient e-folding: Fine Tuning Still Necessary? • Density Perturbation: Largely Unaffected • Post-Inflation: • Reheating: Closed to Open • Baryogenesis • Nucleosynthesis • Structure Formation and Dark Matter How is the Standard Model embedded?

7. Repopulating a Brane World • Is there a viable standard model or GUT world? • Is there a viable baryogenesis? • Is there a viable nucleosynthesis?Can the standard model sector drive the expansion of the universe at the time of nucleosynthesis? • Cold dark matter today?

8. Brane Inflation in a Nutshell Calabi-Yau Standard Model + ……

9. How to make the inflation scale much lower than the Planck scale / the string scale?

10. Flux Compactification with a Hierarchy: Warped Calabi-Yau with a Klebanov-Strassler Throat 3+1 dimensional world internal geometry

11. Klebanov-Strassler Throat Klebanov+Strassler, 2000

12. Hierarchy Giddings+Kachru+Polchinski, 2001

13. KS Throat Attached to a Compact Calabi-Yau is a Randall-Sundrum Scenario (I) Realized as a String Theory Solution

14. Hierarchy and Inflation (KKLMMT) anti D3’s D3’s Kachru+Kallosh+Linde+Maldacena+McAllister+Trivedi, 2003

15. What happens after the branes meet and annihilate?

16. Unstable D-Brane System states can be GSO truncated from all strings except for A coincident pair of D-brane / anti D-brane will annihilate viaTachyon Condensation A.Sen hep-th/9805170

17. Annihilation D3 Anti-D3 PY hep-th/9901159

18. V(T) T Unstable D-Brane System: Effective Field Theory Sen Garousi Kluson Bergshoeff et.al 1999 tachyon conserved electric flux = fundamental string charge

19. Minimal Case:

20. Tachyon Matter A. Sen 2002 Ideal Fluid of Massive Particles (Tachyon Matter)

21. With Net Fundamental String Fluxes: Gibbons+Hori+PY, 2000 Fundamental string charge Conserved momentum Ideal Fluid of Massive Particles (Tachyon Matter) + Ideal Fluid of Relativistic Flux Lines (String Fluid) With Mutual Interaction

22. Ideal Fluid of Massive Particles (Tachyon Matter) + Ideal Fluid of Relativistic Flux Lines (String Fluid)

23. With 1+1 Dimensional Mutual Interaction Governed by a Deformed Light-Cone Gibbons+Hashimoto+PY 2002 Deformed 1+1 Dimensional Light-Cone Along the Length of the Flux Lines: Free propagation of signals along the flux lines with reduced speed of light: Static solutions are all homogeneous along the flux line and arbitrary in other directions. Usual Light-Cone in p+1 Dimension

24. Closed String Interpretation Fluids in Open String Picture

25. Closed String Interpretation Fluids in Open String Picture A. Sen 2003

26. Closed String Interpretation Fluids in Open String Picture H-U Yee+PY, 2004

27. How to see this ?

28. Take a limit of no string fluid = no fundamental string charge Tachyon matter only = String oscillator modes only Collection of heavy closed stringswith oscillators excited

29. Decaying Boundary State Sen Sen+Mukhopadhay Rey+Sugimoto 2002

30. Spectroscopy (I) of the Decaying D-Brane Lambert+Liu+Maldacena, 2003 cf) Chen+Li+Lin 2002

31. Spectroscopy (II) Exponential suppression on (transverse) momenta: Small width on velocity dispersion This feature translates to boundary state proof of Gutperle+PY, 2004

32. Lessons: • Unstable D-Brane (or D-anti-D) decays to highly excited closed strings of level instead of “radiating away.” • Once we take account string coupling, the producedclosed strings will further decay to lighter string states. • Tree level Open String Theory knows about classical Closed Strings:Why?Closed Strings as coherent states of Open Strings?Open Strings as a fundamental building block?

33. Reheating

34. Brane inflation has a very effective reheating mechanism as far as quickly producing a lot of matter energy goes, but… Can we deposit energy predominantly to the standard model sector after the end of a brane inflation? Is there a viable nucleosynthesis? Can the standard model sector drive the expansion of the universe at the time of nucleosynthesis? How much energy is deposited in the form of massless gravitons and semi-stable dark matter?

35. (P)Reheating from the Decaying D-Brane Energy is deposited to massive particles with little kinetic energy, almost evenly in each mass range, up to

36. D-Brane Decay and (P)Reheating D3’s or anti-D3’s leftover

37. Cascade to Localized KK Modes D3’s or anti-D3’s leftover Localized KK Modes

38. Bulk Modes Localized String Modes Localized KK Modes Initial Energy Deposit Cascades to Lighter KK Modes

39. Reheating for a single throat scenario Calabi-Yau with a single warped throat Kofman+PY, 2005

40. Triple Stage Reheating for a Single Throat: • Preheating: Production of Heavy Closed Strings • Decay to Local KK Modes and Thermalization • Decay to Open String Sector and Thermalization

41. (assuming wide throat)

42. Multi-Throat Cases? Inflation Throat Energy transfer via Tunneling Standard Model Throat Classical processes cannot do the job right, for it leave behind to much gravitational energy

43. Quadruple Stage Reheating for Multi-Throat: • Preheating: Production of Heavy Closed Strings • Decay to Local KK Modes and Thermalization • Tunneling to a Longer “Standard Model” Throat and Thermalization of Local KK Modes in that Throat • Decay to the Standard Model Sector and Thermalization

44. Mix and Decay Inflation Throat Standard Model Throat Issues: - mixing mass matrix between KK modes - larger number of states in the 2nd throat - large decay width in the 2nd throat - oscillation and decay

45. Basics of Two-Level Oscillation Small mass difference induces large mixing at the cost of slow time dependence; Large mass difference suppresses mixing

46. Basic Facts about localized and free KK modes in a KS Throat Mass Gap Naïve Number of States m < M Probably not, but longer throat should have more KK modes

47. Is the larger number of states in the 2nd throat an advantage for the reheating into the 2nd throat ?

48. Is the larger number of states in the 2nd throat an advantage for the reheating into the 2nd throat ?

49. Is the larger number of states in the 2nd throat an advantage for the reheating into the 2nd throat ? mixing further suppressed by the decay width (= imaginary mass)

50. Is the larger number of states in the 2nd throat an advantage for the reheating into the 2nd throat ? mixing further suppressed by the decay width (= imaginary mass)