1. 1 Pisin Chen Department of Physics and Graduate Institute of Astrophysics & Leung Center for Cosmology and Particle Astrophysics National Taiwan University & Kavli Institute for Particle Astrophysics and Cosmology Stanford University 2 nd LeCosPA International Symposium, Taipei, Dec. 14-18, 2015

2. 2 Black Hole: predicted by Einstein’s GR and observed in space

3. Black hole Hawking evaporation – Connecting GR, QM, SM in one stroke 3

4. Hawking evaporation may result in the loss of information! Fundamental conflict between general relativity and quantum field theory!! First pointed out by Hawking himself in 1978 Endless debates ever since Solutions include “black hole complementarity” (Susskind et al.), Firewall (AMPS, AMPSS), etc. Entanglement between Hawking radiation and partner particle Wilczek 1987, Schutzhold-Unruh 2010, Hotta-Schutzhold-Unruh (2015) Balck hole remnants (Chen-Ong-Yeom, 2015) Naked firewalls (COPSY, 2015) Latest: Hawking-Perry-Strominger (2015)? etc., etc., etc. 4

5. A glance at the information loss paradox 5 PC, Yen Chin Ong, Dong-han Yeom, Phys. Reports (2015)

6. Investigations of ILP mostly theoretical. Astro black holes too huge and too young. 6

7. Analog Black Holes Sound waves in moving fluids – “dumb holes” Unruh (1981, 1995) Traveling index of refraction in media Yablonovitch (1989) Violent acceleration of electron by lasers Chen-Tajima (1999) Electromagnetic waveguides Schutzhold-Unruh (2005) Bose-Einstein condensate Steinhauer (2014) Accelerating mirror Fully-Davies (1976), Davies-Fulling-Unruh (1977), Birrell- Davies (1982), Carlitz-Willey (1987), Hotta-Schutzhold-Unruh (2015)… 7

8. Unruh Effect vs. Hawking Effect 8

9. Probing Unruh effect with intense lasers 9 Chen-Tajima PRL (1999): Standing (or transient) wave by two equal, counter-streaming linearly polarized laser pulses. Test particle ( ) put at nodal point where Unruh radiation isotropic in the electron rest frame Concentrated in the forward cone, which happens to be in the `blind spot’ of the competing background Lamor radiation.

10. Dramatic Adv. in Laser Technology 10 Esirkepov-Bulanov (2002)

11. Plasma wakefield acceleration Tajima-Dawson (1979)- Driven by laser Chen-Dawson-Huff-Katsouleas (1985)- Particle beam driven 11 Acceleration of O(100) GeV/m observed !

12. Relativistic Plasma Mirror Bulanov, Esirkepov, Tajima (2003) 12

13. Relativistic Plasma Mirror Courtesy: G. Mourou 13 Bulanov (2001), Mourou-Tajima-Bulanov (2006)

14. Relativistic Plasma Mirror Courtesy: G. Mourou 14

15. Relativistic mirror Courtesy: G. Mourou 15

16. Accelerating plasma mirror Born relativistic Laser velocity in plasma can be accelerated and therefore its wakefield Acceleration can increase in time and stop abruptly 16 What can it offer? What it cannot offer? Being in flat space, unitarity preserved: no loss of information No singularity either No Page time No firewall Investigation of correlation of partner modes and possible final outburst of energy

17. Plasma Mirror is like a tsunami 17

18. An accelerating plasma mirror The plasma wakefield, i.e., the relativistic mirror, is induced instantly by the impinging laser, with Nonlinear plasma wakefield is described by the (normalized) scalar and vector potentials and by the coupled equations 18

19. The deceleration (or redshift) of the laser (and therefore the mirror) is governed by Let us model the laser envelope as Then the solution is and 19 Natural tendency of laser deceleration due to wakefield excitation

20. Artificial inducement of acceleration by introducing plasma density gradient Two operating regimes Regime I: Plasma mirror follows right behind the laser. Phase velocity = group velocity Regime II: Plasma mirror trails far behind laser. The dispersion relation changes to 20 t is the time of laser Propagation in plasma

21. Plasma density variation 21 otherwise

22. Regime I In this regime where the refractive index In the nonlinear regime typically Then we find Demanding that 1 st term >2 nd term, we get 22 Due to density gradient Due to frequency redshift

23. Regime II This regime actually works better. Recall that So what one needs is to make Increasing plasma density. 23

24. Example Plasma target based on nanotechnology with thickness X=1500nm and density from to Take double advantage of plasma mirror: 1. Use it to create x-ray pulse at 10nm. 2. Inject it into the above target to create accel. mirror. 24 Corresponding Unruh temperature:

25. Correlation of Partner Particles Final outburst of energy or not? 25 Hawking particle partner particle Vacuum fluctuations Worldline of the plasma mirror Correlation between the two modes Partner particle entanglement: F. Wilczek (1989) Schutzhold-Unruh (2010) Hotta-Schutzhold-Unruh (2015) Hotta-Sugita (2015)

26. 26 Penrose diagram for accelerating plasma mirror

27. Summary Hawking evaporation and information loss paradox is one of the most critical issues in physics. So far most investigations are limited to theoretical studies. Quantum entanglement between Hawking radiation and partner particle may reveal the secrete. Accelerating/decelerating relativistic plasma mirrors may serve to address some aspects of this paradox experimentally. In addition to high energy particle acceleration for particle physics, plasma wakefields can investigate black hole physics with simple setup & state-of-the- art lasers. Plasma target thermal noise may be a challenge. 27