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Fundamental physics in our time Gerhard Schäfer Institute of Theoretical Physics

Fundamental physics in our time Gerhard Schäfer Institute of Theoretical Physics. from quantum to cosmos(2), bremen, june 10 - 13, 2007. from quantum to cosmos. In 1968 J. Schwinger formulated empirical scaling laws that interconnect the cosmos, the laboratory, and the atoms

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Fundamental physics in our time Gerhard Schäfer Institute of Theoretical Physics

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  1. Fundamental physics in our timeGerhard SchäferInstitute of Theoretical Physics from quantum to cosmos(2), bremen, june 10 - 13, 2007

  2. from quantum to cosmos In 1968 J. Schwinger formulated empirical scaling laws that interconnect the cosmos, the laboratory, and the atoms , Does the quantum stabilize the cosmos?

  3. from quantum to cosmos empirical law (Zel`dovich 1967/68):

  4. goals of fundamental physics (FP) • FP is exploring the basic aspects of Nature • Space and time • Particles and fields • FP aims at • Finding more comprehensive concepts and laws • Testing the existing ones • Resolving basic inconsistencies • FP includes • Unification of the fundamental forces • Discovery of new particles and fields • Test of GR and of the equivalence principle • Verification and exploration of black holes • Detection and observation of gravitational waves

  5. current problems in FP Mathematical problems • Grav. waves astrophysics • Global aspects of spacetime • Unification of all forces • Phase transitions Conceptual problems • Dark Energy & Dark Matter • Big Bang & Inflation • Black Holes • Irreversibility of phys. proc. Experimental problems • Gravitational Waves • Black Holes • Big Bang & Inflation • Dark Energy & Dark Matter Need for Space Missions

  6. Why missions in space? • Space conditions • Infinitely long gravity-free environment • Large gravitational potential differences • Large velocity differences • Quiet environment • Straight view to the Universe

  7. frame theories • Special RelativityEinstein 1905 • General RelativityEinstein 1915 • Quantum Theory Heisenberg 1925Schrödinger 1926Dirac 1927 non-relativistic relativistic

  8. special relativity (SR) • Fundamental principle: constancy of speed of light c = universal constant • Unification of space and time: spacetime • Poincare´ group; causality cone • Proper time and action

  9. universally constant general relativity (GR) • Fundamental principle: Equivalence Principle • Unification of inertia and gravity: curved spacetime • Group of coordinate transformations; horizons • Proper time and spacetime metric

  10. quantum theory (QT) • Fundamental principle: Superposition Principle • Unification of particles and waves: probability amplitudes • Unitary group; coherence • Antimatter

  11. Spin in SR & GR & QT • SR: min. transvers. extension of body with massm and spin S • GR: radius of ring singularity of Kerr BH • QT: Compton wavelength • QT: transversal extension of massless particle

  12. dynamical theories • electrodynamics [U(1)]: photon quarks, leptons (charged) infinite range • weak int. th. [SU(2)]: Z-, W-bosons quarks, leptons • chromodynamics [SU(3)]: gluon quarks • U(1) x SU(2) - unified theory [Higgs boson] • GR [GL(4)]: gravitation infinite range

  13. from microphysics to macrophysics • Transition from coherence to incoherence • Transition from time to temperature: • Arrow of time: • No quantization of time: negative prob.

  14. GR and the quantum • Unification of gravity with electro-weak and strong interaction • Observation: General Relativity • is effective theory (low-energy limit): : vacuum-expectation valueof fundamental field at present epoch • - term is of vacuum-energy type with pressure

  15. GR and the quantum • Unification-Ansatze: String and brane theories in higher-dimensional spacetimes with non-trivial topologies • However, the effective cosmological constant is infinitesimal by particle-physics standards • Quintessence scenarios

  16. B B B A A B A A t cosmology • Curvature • Hubble parameter • Deceleration parameter

  17. cosmology

  18. Energy and Matter in the Universe accelerated expansion at present epoch

  19. inflation area

  20. inflation - inflaton • action of massive scalar field • action of 3-dimensional spaces (space-slices)

  21. `´square root`´ of GR • square root of metric: tetrad field invariance group: local Lorentz group [S0(3,1),SL(2,C)] • connection to SUSY (unification of fermions and bosons)

  22. string theory • action of point particle (m = m[i] = m[pg] = m[ag]) • action of global part of 3-dimensional spaces • action of string

  23. Univ. free fall • Lorentz invariance • Univ. grav. red shift • Constancy of fund. const. Einstein‘s Equivalence Principle metric gravity Einstein field eqn Grav. field Matter Geodetic eqn the structure of gravity • Foundations of GR

  24. equivalence principle (EP) • Why testing the EP in Space? • The EP is deduced from experimental facts by `infinite‘ extrapolation. • Present fundamental physics framework is incomplete. • The most sensitive low-energy tests of new, gravity-related theories are those involving the EP. • There exist theoretical models which predict a violation of the EP at a level that is smaller than the presently tested level of about 10-13 but could be within reach of a Space experiment.

  25. universality of free fall g • Action of point mass: • Violation of EP: fundamental field • Acceleration of mass 1: • cosmological value

  26. test of EP – the concept • Why testing the EP in Space?

  27. Metric gravity the structure of gravity • Framework: PPN-formalism (variable G included)

  28. the structure of gravity • Non-cosmological effects of the gravitational field • Perihelion shift • Deflection of light • Grav. redshift • Time delay • Gravitomagnetism • Gravitational waves • Black holes

  29. the binary pulsar • Hulse-Taylor pulsar (PSR B1913 + 16)

  30. polarization of gravit. wave in GR

  31. gravitational wave detectors in space • Fundamental Physics with gravitational-wave detectorsin space • Gravitational waves • Black holes/strong-field GR • direct confirmation of existence of Black Holes • Measurement of Lense-Thirring effect better than 1% • Cosmological background: • Direct signature of cosmic strings and/or inflation • Observation of conditions close to Big Bang • Measurement of total density of the Universe,determination of all dark matter

  32. black holes Schwarzschild radiusHorizon

  33. Einstein-Rosen bridge

  34. Schwarzschild geometry

  35. GR and the quantum W. Israel in 2003: You can pick anyone off the street and say `Einstein´. They will at once write . But if you ask what this formula means, the response will be quite different. At best, you may get some mumbling about `atomic bomb´. It is sobbering that after a quarter-century we are in a hardly better position regarding the formula

  36. missions & main FP objectives ASTROD, Bepi-Col., Gaia, LATOR, Cassini, GP-B, LAGEOS: PPN-metric ACES/PHARAO: PPN-metric, foundations of GR GG, MICROSCOPE, POEM, STEP: equivalence principle LISA: gravitational waves, black holes, big bang Constellation-X:black holes, dark matter Planck: dark matter, dark energy GAUGE: unification of forces

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