1. The CMB anomalies with a bouncing inflation 朴云松（ Y.S. Piao ）

2. I. The motivation: CMB anomalies II. Our viewpoint: CMB anomalies is a hint of preinflationary physics III. Our model Based on collaboration with Guo and Liu arXiv:1304.6527

3. I. The motivation Inflation is the current paradigm of early universe.

4. I. The motivation The Planck’s results No Non-Gaussiangity No running

5. The Planck’s results I. The motivation

6. The Planck confirmed 1. deficit of power on large angular scales

7. I. The motivation The Planck confirmed 2. power asymmetry on large angular scales Dipole modulation

8. II. Our viewpoint Why both the deficit of power and the power asymmetry appeared simultaneously on large angular scales ? We think this is not accidental.

9. Dipole modulation The CMB power asymmetry may be modeled as a dipole modulation of power. Erickcek et.al Lyth, fluctuation mode

10. Dipole modulation The modulation can be explained in light of Lyth, Liu, Guo, Piao

11. Dipole modulation is determined by the observation on corresponding scales The result is < 0.1 Erickcek et.al Lyth, Thus for single inflation model which is not consistent with Planck data.

12. II. Our viewpoint We think: both the large modulation and the deficit of power implies on large angular scales the anomalies on large angular scales is a hint of the preinflationary physics.

13. III. Our model Ten years ago

15. III. Our model

16. III. The bounce model Before 03, modified gravity Pre-big bang, ekpyrotic universe After 03, GR and field breaking null energy condition Ghostfree models ghost condensation (new ekpyrotic universe), G-bounce a t Any of these mechanisms may apply to our model, the result is not affected, since the bounce does not alter the spectrum of primordial perturbation.

17. III. Our model before the bounce, the field will climb up along its potential. after the bounce, It rolls down. The scenario: initially the universe is in a contracting phase, then it bounces into a slow roll inflationary phase.

18. III. Our model The evolution of background (numerical)

19. III. Our model The evolution of background is approximately is the comoving Hubble scale at matching surface

20. III. Our model The equation of is where is defined,

21. III. Our model In the contracting phase In the inflationary phase

22. III. Our model all physical quantities should continuously pass through the bounce. Liu, Piao, Phys.Rev.D86, 083510 (2012)

23. III. Our model Thus the continuity of brings

24. III. Our model

26. Planck used cutoff model Our model

27. III. Our model

28. The implication to the eternal inflation scenario in landscape the bouncing inflation is a favored channel to implement the slow roll inflation.

29. IV. Conclusion The anomalies appeared simultaneously is not accidental, which is a significant hint of Pre-inflationary physics. the string theory ?

30. Thank You!