Workshop on Transplanckian Physics

1. Workshop on Transplanckian Physics Uppsala, 24-26 october 2002 http://www.teorfys.uu.se/PEOPLE/domert/nordic/index.html

2. Review ofStandard Big Bang Cosmology

3. Standard BB Cosmology • Hubble Law (20’s) and redshift • CMBR (60’s and today) • Nucleosynthesis • Age of the Universe • Expansion Models • Dark Matter/Energy • Other models: steady state model, …

4. History of the Universe (with Inflation)

5. CMBR angular power spectrum Dipole anisotropy (Conklin, 1969)

6. CMBR Anisotropy http://www.astro.ucla.edu/~wright/CMB-DT.html

7. Why Transplanckian Physics? • Standard BB cosmology presents some open issues: • The Flatness Problem • The Entropy Problem • The Horizon Problem • Structure formation + CMBR inhomogeneities • matter/antimatter asimmetry, dark matter, ...

8. Workshop on Transplanckian Physics Uppsala, 24-26 october 2002 http://www.teorfys.uu.se/PEOPLE/domert/nordic/index.html

9. Program U. DanielssonCan Planck see transplanck? O. ElgaroeyNeutrino properties from the 2dF Galaxy Redshift Survey M. GiovanniniThe pre-big bang scenario confronts observations D. GrassoCosmology with gravitational wave detectors F. Hassan1. Introduction to the Theory of Cosmological Perturbations2. Introduction to the Trans-Planckian Problem in Inflationary Cosmology A. JokinenBaryogenesis through Affleck-Dine mechanism N. KaloperInflation and Short-Distance Physics E. K.VakkuriCosmological toy models in string theory M. LaineHigher dimension induced domain wall defects in our world J. NiemeyerModels and Signatures of Short Distance Physics in Inflation S. RäsänenThe ekpyrotic scenario/cyclic model: status report M. SlothTransplanckian effects in inflationary cosmology and the modified uncertainty principle A. StarobinskyTrans-Planckian particle creation now and in the past I. WehusScalar field potential in 5-dimensional Kaluza-Klein theory

10. Theories vs Experiments (1) • Theories / Toy models: • Standard Big Bang Cosmology (starting point) • Inflation • Theory of Cosmological Perturbations • Pre-Big Bang scenario • Ekpyrotic scenario / cyclic model • ...

11. Theories vs Experiments (2) • Typical signatures • Look for theories with a ”good” footprint • Experiments: • Gravitational waves detectors • Supernova Project • CMBR survey • Neutrino studies • UHECR • PAMELA, ...

12. During inflation: a(t) ~ exp[H(t)·t] Typical numbers: 60 e-foldings; 10-33sec (start:10-37 after BB) Some formalism + Inflation FRW line element: Friedmann eq. Einstein eq. ”These numbers are like George Bush military budget...”

13. Theory of Cosmological Perturbations • Standard Big Bang formalism & theory • Perturbation theory • Density inhomogeneities amplified by gravity (ex. / ~ 10-5 after 300000 yrs may explain structure formation) Riotto, hep-ph/0210162 Inflation and the theory of cosmological perturbations

14. Trans-planckian Problem in Inflationary Cosmology In most current modelsof inflation, the periodof exponential expansion lastsso long that at the beginning of inflation, scales of cosmologicalinterest today had a physical wavelength muchsmaller than the Planck length, and the theories used tocompute the spectrum of fluctuations are known to breakdown on these scales.

15. The pre-big bang scenario confronts observations Massimo Giovannini, University of Lausanne Abstract: “The key features of the pre-big bang scenario will be presented in light of its possible phenomenological relevance. Recent developments will also be discussed with particular attention to possible implications for CMB physics and relic GW backgrounds. A personal view of the speaker on the future (possible) directions of this scenario will also be given.”

16. Pre Big-bang Scenario Inflation after BB Inflation before BB Figures from: http://www.ba.infn.it/~gasperin/

17. Cosmology with gravitational wave detectors Dario Grasso, Scuola Normale Superiore, Pisa Abstract: “The new generation of gravitational waves detectors under construction/project may be able to detect stochastic backgrounds of cosmological origin. A short panoramic on the most promising sources and the characteristics of the expected signals will be given.”

18. GW Production • GW background from amplification of vacuum fluctuations • Standard inflation • Pre-Big Bang cosmology • Other models • Known astrophysical sources • Noise (unresolved astrophysical sources) • On Earth: Seismic noise

19. GW from a Pre-BB Model http://www.ba.infn.it/~gasperin/

20. VIRGO Sensitivity

21. VIRGO http://wwwlapp.in2p3.fr/virgo/gwf.html

22. Ekpyrotic Scenario • One visible 3-D brane + one 3-D hidden brane in a 11-D space • Brane oscillations induce energy transfer (BB in our brane) • Old, new + cyclic scenario (all: 2001) Figures from: http://www.sciencenews.org/20010922/bob9.asp

23. Classical uncertainty principle & commutation relation Modified uncertainty principle xp  ½ xp  ½( 1 + (p)² + ... ) [x, p] = i(1+p²) [x, p] = i The Stringy Uncertainty Principle Hyphotesis: there is a minimum resolution xmin = ½ J. Niemeyer, Models and Signatures of short distance physics in inflation M.Sloth, Transplanckian effects in inflationary cosmology and the modified uncertainty principle

24. In case a singularity appears in the theory: “...then a miracle occurs...” Sentences of the Day “If a matematician would look at what we are doing, he wouldn’t be happy!” “They are never happy”