暗能量和宇宙学 CPT 破坏

1. 暗能量和宇宙学CPT破坏 李明哲 南京大学物理系 粒子-核-宇宙学联合研究中心

2. Outline 1, Brief review on dark energy models, cosmological constant or dynamical dark energy, current status 2, Interacting dark energy: direct coupling: propagates long range force, spoils the flatness of the potential of dark energy derivative coupling: spin-dependent force, shift symmetry, guarantee the flatness of the potential, cosmological CPT violation 3, Model: Leptogenesis Anomaly for CMB 4, Conclusion

3. Brief Review on Dark Energy Accelerating Universe ->Dark Energy SN Ia (SCP, HZT….) LSS (2dfGRS, SDSS…)

4. CMB experiments

5. No antimatter Dark matter? Dark energy? Why no antimatter? ……

6. Negative pressure Candidates: 1, Cosmological constant Cosmological constant problem! S. Weinberg, RMP (1989)

7. 2, Dynamical dark energy Quintessence: Flat potential Phantom: K-essence: Cannot cross -1, no-go theorem Feng, Wang & Zhang, PLB(2005);Vikman, PRD(2005);Zhao, Xia, Li, Feng & Zhang, PRD(2005); Xia, Cai, Qiu, Zhao &Zhang, IJMPD(2008) Quintom: crosses -1 Feng, Wang & Zhang, PLB(2005) Li, Feng & Zhang, JCAP(2005) Cai,Li,Lu,Piao,Qiu&Zhang, PLB(2007) ………

8. It is important to determine w of DE by cosmological observations! Parameterization of equation of state: A) w=w_0+w_1 z (for small z) B) w=w_0+w_1 z / (1+z) (used mostly in the literature) C) w=w_0+w_1 sin(w_2 ln(a)+w_3)

9. Current constraint on the equation of state of dark energy Quintom A Quintessence phantom Quintom B Xia, Li, Zhao, Zhang, PRD(2008) WMAP5result E. Komatsu et al., arXiv:0803.0547 Status: 1) Cosmological constant fits data well; 2) Dynamical model not ruled out; 3) Best fit value of equation of state: slightly w across -1  Quintom model

10. Interacting Dark Energy Dynamical dark energy is expected to have interactions to the rest of the world besides the gravity. Two types of couplings: direct & derivative 1, direct coupling A. Long range force Constrained tightly! S.M. Carroll, PRL(1998) B. Instability under quantum corrections

11. 2, derivative coupling: 1, obeys the shift symmetry which guarantees the flatness of the potential. 2, propagates spin-dependent force, short range, much weaker constraint from astrophysics PDG(2002) Violates Lorentz and CPT symmetry because cosmological CPT violation!

12. Cosmological CPT violation and baryogenesis The universe is not symmetric between matter and antimatter We need baryogenesis Sakharov conditions for baryogenesis: • Baryon number non-conserving interaction • C and CP violations • Departure from thermal equilibrium Precondition: CPT is conserved! Cohen & Kaplan, PLB(1987)

13. Interacting dark energy and baryogenesis A unified picture of matter-antimatter asymmetry and dark energy!

14. Quintessence model with tracking solution Albrecht & Skordis, PRL(2000) Copeland, Liddle & Wands, PRD(1998).

15. Bean, Hansen & Melchiorri, PRD(2001); Doran & Robbers, JCAP(2006)

16. Comments: 1, The electroweak Sphaleron violates B+L and will make as low as 100GeV, M should be GeV Kuzmin, Rubakov&Shaposhnikov,PLB(1985) 2, If M is higher, e.g., GUT scale or Planck mass scale, the generated baryon number asymmetry would be very small compared with the observation. 3, In this case, we turn to leptogenesis

17. The Model Mingzhe Li, Jun-Qing Xia, Hong Li, Xinmin Zhang, PLB (2007)

18. the decoupling temperature of B-L violating interaction. Sphaleron conserves B-L and converts B-L asymmetry generated above to a same order of baryon number asymmetry.

19. Baryon isocurvature perturbation Adiabatic or isothermal: Isocurvature or entropy: In our case The fluctuation of the dark energy scalar field will induce a nonzero baryon isocurvature perturbation

20. The quintessence model with potential Consistent with the observations!

21. In our model of baryo/leptogenesis The CPT violation is very small, was large to generate enough baryon number asymmetry in the early universe.

22. This CPT violation can be observed by CMB polarization experiments!

23. The full lagrangian of photons The action integral is gauge invariant. Geometric Optics Approximation

24. Basic equations:

25. Polarization and Stokes parameters At the inertial frame I→ intensity Q&U→ linear polarization V→ circular polarization The polarization angle:

26. Local Lorentz frame

29. CPT violation induced the rotation of the polarization direction Rotation angle only depends on the difference of dark energy field at the source and the observer’s positions. Which characterize such CPT-violating effect!

30. Observation of cosmological CPT violation through CMB experiments

31. Without CPT violation, the correlations of TB and EB vanish In the case of homogeneous

35. 1) Bo Feng et al., PRL 96, 221302 (2006) 2) WMAP3 only P.Cabella, Natoli & Silk, PRD (2007) 3) J.Q.Xia et al., arXiv:0710.3325 WMAP5 only 4) (WMAP Group) Komatsu et al., arXiv:0803.0547 5) J.Q.Xia et al., arXiv:0803.2350 6) J.Q.Xia et al., arXiv:0710.3325

36. Spatial dependent rotation angle: Mingzhe Li & Xinmin Zhang, PRD(2008)

39. This is the direct consequence of invariance of under the rotation Only the background evolution of dark energy provides CPT violation!

40. The corrections are at the order of In the quintessence model with tracking potential, By assuming the initial fluctuation of quintessence generated from a GUT scale inflation

41. Detection of Spatially Dependent Rotation Angle How to De-Rotate the Cosmic Microwave Background Polarization.M. Kamionkowski, PRL(2009), arXiv:0810.1286 Constraining a spatially dependent rotation of the Cosmic Microwave Background Polarization.Yadav, Biswas, Su, Zaldarriaga,arXiv:0902.4466

42. Conclusion • Dynamical dark energy has possible couplings besides gravity to other matter. Direct couplings are constrained tightly. Derivative couplings are more likely. • The derivative couplings violate CPT cosmologically and can explain the matter-antimatter asymmetry. • Our model of leptogenesis predicts CPT violation in the photon sector. It can be tested by CMB, current data favored nonzero rotation angle mildly. • The rotation angle is anisotropic in general. More studies in the future.

43. Thanks!

44. Date: Wed, 8 Oct 2008 21:04:24 -0700From: Marc Kamionkowski <kamion@tapir.caltech.edu>To: Zhang XinMin <xmzhang@mail.ihep.ac.cn>Subject: polarization rotationHi Xinmin,Enclosed below is a paper that you might be interested in. It follows on work that you finished just recently.Cheers,Marc

45. From: Meng Su <mengsu@cfa.harvard.edu> To: xmzhang@mail.ihep.ac.cn Date: 2009-02-27, 15:32:45Subject: Greetings from Meng Su Dear Prof. ZhangThis is Su Meng if you still remember:) Now I'm studying at HarvardUniversity working with Prof. Matias Zaldarriaga. Haven't met you for awhile, how is everything going with you?Recently you had a work with Dr. Li Minzhe about spacial dependent rotationof CMB polarization. I thought it is very interesting! I wrote an email toDr. Li but didn't get reply... So Kamionkowski after then had a work aboutreconstruct the rotation field from CMB polarization. I suggested peoplehere to work on this topic and we just have a paper online arXiv: 0902.4466.First of all, I hope this paper cite your previous papers on this topicswell:)………………………….Best regards,Meng Su