Fundamental physics in our time Gerhard Sch

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

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from quantum to cosmos

• empirical law (Zeldovich 1967/68)

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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

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current problems in FP

• Conceptual problems
• Dark Energy Dark Matter
• Big Bang Inflation
• Black Holes
• Irreversibility of phys. proc.

• Mathematical problems
• Grav. waves astrophysics
• Global aspects of spacetime
• Unification of all forces
• Phase transitions

• Experimental problems
• Gravitational Waves
• Black Holes
• Big Bang Inflation
• Dark Energy Dark Matter

Need for Space Missions
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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

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frame theories

• Special Relativity
  Einstein 1905
• General Relativity
  Einstein 1915
• Quantum Theory

Heisenberg 1925Schrödinger 1926Dirac
1927
non-relativistic
relativistic
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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

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general relativity (GR)

• Fundamental principle Equivalence Principle
• Unification of inertia and gravity curved
  spacetime
• Group of coordinate transformations horizons
• Proper time and spacetime metric

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quantum theory (QT)

• Fundamental principle Superposition
  Principle
• Unification of particles and waves
  probability amplitudes
• Unitary group coherence
• Antimatter
  
  

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Spin in SR GR QT

• SR min. transvers. extension of body with mass m
  and spin S
• GR radius of ring singularity of Kerr BH
• QT Compton wavelength
• QT transversal extension of massless particle

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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

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from microphysics to macrophysics

• Transition from coherence to incoherence
  
• Transition from time to temperature
• Arrow of time
• No quantization of time
  negative prob.
  

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GR and the quantum

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

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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

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cosmology

• Curvature
• Hubble parameter
• Deceleration parameter

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cosmology
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Energy and Matter in the Universe

• accelerated expansion at present epoch

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inflation area
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inflation - inflaton

• action of massive scalar field
• action of 3-dimensional spaces (space-slices)

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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)

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string theory

• action of point particle (m mi mpg
  mag)
• 
  
• action of global part of 3-dimensional spaces
• action of string

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the structure of gravity

• Foundations of GR

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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.

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universality of free fall

• Action of point mass
• Violation of EP
  fundamental field
• Acceleration of mass 1
• 
  cosmological value

g
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test of EP the concept

• Why testing the EP in Space?

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the structure of gravity

• Framework PPN-formalism (variable G included)

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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

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the binary pulsar

• Hulse-Taylor pulsar (PSR B1913 16)

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polarization of gravit. wave in GR
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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

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black holes
Schwarzschild radiusHorizon
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Einstein-Rosen bridge
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Schwarzschild geometry

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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
  
  
• 
  

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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