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Astroparticle Physics: Primordial Black Holes Quantum Gravity

Astroparticle Physics: Primordial Black Holes Quantum Gravity. Frank Krennrich, Iowa State University. Outline. Primordial Black Holes: - Hawking Radiation - formation scenarios - observational limits

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Astroparticle Physics: Primordial Black Holes Quantum Gravity

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  1. Astroparticle Physics: Primordial Black Holes Quantum Gravity Frank Krennrich, Iowa State University Colloquium, Iowa State University

  2. Outline • Primordial Black Holes: - Hawking Radiation - formation scenarios - observational limits - air Cerenkov burst technique - prospects with more glas • Quantum Gravity: - motivation - observational limits - prospects with large collection area Ground-based -ray Astronomy Towards the Future

  3. dM/dt ~ Lifetime t ~ M3 Hawking Radiation Temperature T: Lifetime t: Mass loss rate: X-ray emission: -) Shift in Peak Energy -) synchrotron cooling  depends on # of particle+resonance states available --> depends on particle physics S. W. Hawking, Nature, 248, 31 (1974) Ground-based -ray Astronomy Towards the Future

  4. dM/dt ~ Lifetime t ~ M3 Hawking Radiation Final burst: - STANDARD MODEL --> t ~ seconds --> Epeak ~ TeV - HAGEDORN MODEL --> t ~ 100 ns --> Epeak ~ 250 MeV THE HAGEDORN MODEL X-ray emission: -) Shift in Peak Energy -) synchrotron cooling R. Hagedorn, A&A, 5, 184 (1970) Porter & Weekes, MNRS, 183, 205 (1978) Ground-based -ray Astronomy Towards the Future

  5. PBH formation Gravit. collapse from local overdensity Particle horizon mass at formation epoch: --> bursts constrain ~ 10-23 s --> diffuse -ray background from 10-43 s …10-23 s density perturbations: - scale invariant fluctuations --> power law  phase transitions: - temporary softening of equation of state --> narrow mass range spectrum Ground-based -ray Astronomy Towards the Future

  6. Limits to PBHs present explosion rate (dn/dM ~ power law) -ray background: 30 MeV … 120 GeV Sreekumar et al., , ApJ, 494, 523 (1998) but clustering likely --> galactic halo anisotropy expected, see also Wright, ApJ, 459, 487 (1996) Antiprotons flux: - from PBHs - C.R. spallation Ground-based -ray Astronomy Towards the Future Krennrich et al. 2005, preliminary

  7. Microsecond burst detection technique Background reduction: • 0.1 – 100 s burst profile:  long Cerenkov pulse • Imaging:  characteristic shape  extremely smooth • No parallax:  VERITAS, large array Krennrich, Le Bohec & Weekes, ApJ, 529, 506 (2000) Ground-based -ray Astronomy Towards the Future

  8. Microsecond burst detection technique S.G.A.R.F.A.C.E. Short GAmma Ray Front Air Cherenkov Experiment Background reduction: • 0.1 – 100 s burst profile:  long Cerenkov pulse • Imaging:  characteristic shape  extremely smooth • No parallax:  VERITAS, large array TeV Electronics 379 379 Signal Splitter 55 FPGA-based trigger - reliable, tunable - 1,800 h data taken - use for future ACT FADCs & XILINX-FPGA 60 ns… 35s XILINX-FPGA based pattern trigger 55 Le Bohec, Krennrich & Sleege, Astropart. Phys., 23, 235 (2005) Ground-based -ray Astronomy Towards the Future

  9. Microsecond burst detection technique S.G.A.R.F.A.C.E. Short GAmma Ray Front Air Cherenkov Experiment Background reduction: • 0.1 – 100 s burst profile:  long Cerenkov pulse • Imaging:  characteristic shape  extremely smooth • No parallax:  VERITAS, large array TeV Electronics 379 379 Signal Splitter 55 FPGA-based trigger - reliable, tunable - 1,800 h data taken - use for future ACT FADCs & XILINX-FPGA 60 ns… 35s XILINX-FPGA based pattern trigger 55 Le Bohec, Krennrich & Sleege, Astropart. Phys., 23, 235 (2005) Ground-based -ray Astronomy Towards the Future

  10. Sensitivity to PBHs Ground-based -ray Astronomy Towards the Future

  11. Fluence Sensitivity to Bursts: 100 ns burst of 250 MeV -rays Min. photon density: ~ 0.1 ’s/m2 Ground-based -ray Astronomy Towards the Future

  12. SGARFACE III with more glas (ACT): • Fluence sensitivity S: - array trigger with all telescopes - probe scales 100 ns … 0.5 ms - 5 years, glas 70 m2 --> 5,000 m2 - FOV 5 degree ---> PBH~ 10-5 pc-3 y-1 • Probe microsecond burst phenomena: - counterparts to giant pulses from radio pulsars? - millisecond pulsars? - GRBs? Ground-based -ray Astronomy Towards the Future

  13. Quantum Gravity Effects I • Dispersion relation for photons Model dependent function effective QG energy scale • Vacuum as a quantum gravitational medium • vacuum responds differently to the propagation of • particles at different energies! • medium contains quantum fluctuations occuring on the • size scale of the Planck length: Ground-based -ray Astronomy Towards the Future

  14. Quantum Gravity Effects II • Dispersion relation for photons For small energies:  series expansion Sign ambiguity • Time delay between photons of different energy Ground-based -ray Astronomy Towards the Future

  15. Quantum Gravity Effects III • Time delay Most noticable: Amelino-Camelia et al, Nature, 393, 763 (1998) • Constraints from GRBs: GRB 930131 (Schaefer, PRL, 82, 4964, 1999) GRB 021206 (Boggs et al., astro-ph0310307)  EQG> 8.3 x 1016 GeV  EQG> 1.8 x 1017 GeV Ground-based -ray Astronomy Towards the Future

  16. Quantum Gravity Effects IV • Constraint from TeV blazars (Mrk 421 flare)  EQG> 4 x 1016 GeV Biller et al. 1999, Phys. Rev. Lett., 83, 2108 Gaidos et al. 1996, Nature, 383, 319 Ground-based -ray Astronomy Towards the Future

  17. Sensitivity beyond VERITAS 10s 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  18. Sensitivity beyond VERITAS 10s 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  19. Sensitivity beyond VERITAS 10s 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  20. Sensitivity beyond VERITAS 10s • Mrk 421, rate~10 Crab • 7 phot./s (VERITAS) • 70 phot./s (Beyond) • 100 ms possible @100 GeV • blazar variability time scale? 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  21. Sensitivity beyond VERITAS • H1426, rate~0.65 Crab • 0.4 phot./s (VERITAS) • 4 phot./s (Beyond) • few s possible @ 100 GeV 10s • Mrk 421, rate~10 Crab • 7 phot./s (VERITAS) • 70 phot./s (Beyond) • 100 ms possible @ 100 GeV 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  22. Sensitivity beyond VERITAS GRB021206: - 15 ms, but photon starved 10s 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  23. Sensitivity beyond VERITAS • GRB021206: • 15 ms, • but photon starved • GRB050904: • z=6.3 10s 1s 0.1s 10ms 1ms 0.1ms Ground-based -ray Astronomy Towards the Future

  24. Summary • PBHs: - particle astrophysics & Cosmology or U.L. ~ 10-5 pc-3 y-1 - ACT burst technique highly sensitive at 200 MeV @ ~ s • Quantum Gravity: - difficult to get much better (EQG > 1017 GeV) with blazar flares - need sources with sub-second variability at 100 GeV at z ~ 0.1 - GRBs at MeV energies photon starved for better constraints • Both topics discovery potential and we should consider them in design e.g., B. Carr: “PBHs are important for Cosmology, even if they do not exist” Ground-based -ray Astronomy Towards the Future

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