1. Phase Transitions and the Perfectness of Fluids Jiunn-Wei Chen National Taiwan U.

2. Shear viscosity measures how “perfect” a fluid is!

3. Review: shear viscosity minimum bound conjecture QCD shear viscosity in the hadronic phase: (a) zero density (w/ Eiji Nakano) (b) nuclear L-G phase transition ( w/ Yen-Fu Liu, Yen-Han Li, Eiji Nakano ) Scalar field theory ( w/ Mei Huang, Yen-Han Li, Eiji Nakano, Di-Lun Yang ) Bulk Viscosity ( w/ Juven Wang )

4. Shear viscosity Frictional force

5. Kovtun, Son, and Starinets (’05) Conjecture: Shear viscosity / entropy density Motivated by AdS/CFT

7. QGP (quark gluon plasma) almost saturates the bound @ just above Tc (Teaney; Romatschke, Romatschke; Song, Heinz ) LQCD, gluon pasma (Karsc h, Wyld; Nakamura, Sakai; Meyer) QGP near Tc, a perfect fluid, SQGP PQGP: Asakawa, Bass, Müller; Xu, Greiner

8. QCD Phase Diagram

9. What happens below Tc?

10. Pion gas ChPT (chiral perturbation theory) Non-perturbative in coupling Boltzman equation Earlier work: Prakash, Prakash, Venugopalan, Welke; Dobado, Llanes-Estrada; Csernai, Kapusta, McLerran

11. JWC, Nakano

12. QCD Phase Diagram

13. The “Landscape” JWC, Li, Liu, Nakano; Itakura, Morimatsu, Otomo

14. The “Landscape” JWC, Li, Liu, Nakano

16. QCD Phase Diagram

17. Lacey et al., PRL 98:092301,2007 Cold Unitary Atoms Rupak & Schafer 2007; NRCFT 2008

18. of Water (Lacey et al.)

19. 2nd-order p.t.: a 0, c = 0 crossover: + No p.t.: a > 0, b > 0, c = 0 1st-order phase transition a > 0, b 0 (JWC, M. Huang, Y.H. Li, E. Nakana, D.L. Yang)

20. Weak coupling Mean field calculation CJT formulism (Cornwall, Jackiw, Tomboulis) Boltzmann eq.

23. QCD Bulk Viscosity Karsch, Kharzeev, Tuchin; Meyer; JWC, Wang

24. Bulk Viscosity Li, Huang Gubser, Nellore, Pufu, Rocha

25. Outlook Universal and behaviors? ( reaches local minimum near p.t. reaches local maximum near p.t.)

26. Mapping QCD phase diagram by ? Locating critical end point (Lacey)

27. Outlook O(1/N) effect, Higher derivative gravity, ( Brigante, Liu, Myers, Shenker, Yaida; Kats, Petrov ) NR AdS/CFT Cold Unitary Atoms Rupak & Schafer 2007; NRCFT 2008

28. Outlook just below Tc for YM

29. f Just one minimum (a < 0)? O(N) model? Large b?

30. w/o flavor changing Invading the bound (I) (KSS; Cohen; Cherman, Cohen, Hohler)

31. Invading the bound (II) (T. Cohen)

32. Invading the bound (III) Higher derivative gravity ( Brigante, Liu, Myers, Shenker, Yaida; Kats, Petrov ): O(1/N) effect could invade the bound. Most recently, BLMSY

34. Question Which shear viscosity is bigger? Liquid or gas water near 100 degree C at 1 atm?

35. Lacey et al., PRL 98:092301,2007

36. Cold Unitary Atoms Rupak & Schafer 2007.

37. Lacey et al., PRL 98:092301,2007 Cold Unitary Atoms Rupak & Schafer 2007. NRCFT Adams, Balasubramanian, McGreevy; Maldacena, Martelli, Tachikawa; Herzog, Rangamani, Ross 2008

38. Lacey et al., PRL 98:092301,2007 Cold Unitary Atoms Rupak & Schafer 2007.