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Cosmodynamics. Quintessence and solution of cosmological constant problem should be related !. Cosmon and fundamental mass scales. Assume all mass parameters are proportional to scalar field χ (GUTs, superstrings,…) M p ~ χ , m proton ~ χ , Λ QCD ~ χ , M W ~ χ ,…
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Quintessence and solution of cosmological constant problem should be related !
Cosmon and fundamental mass scales • Assume all mass parameters are proportional to scalar field χ (GUTs, superstrings,…) • Mp~ χ , mproton~ χ , ΛQCD~ χ , MW~ χ ,… • χ may evolve with time • mn/M : ( almost ) constant - observation! Only ratios of mass scales are observable
Dirac’s hypothesis The very small dimensionless numbers in physics are due to huge age of the universe . (A) may be true for ratio of dark energy over M4
Dilatation symmetry • Lagrange density: • Dilatation symmetry for • Conformal symmetry for δ=0
Dilatation anomaly • Quantum fluctuations responsible for dilatation anomaly • Running couplings: • V~χ4-A , Mp(χ )~ χ • V/Mp4 ~ χ-A : decreases for increasing χ !! • E>0 : crossover quintessence
Cosmology Cosmology : χ increases with time ! ( due to coupling of χ to curvature scalar ) “ late time cosmology explores the ultraviolet” for large χ the ratio V/M4 decreases to zero Effective cosmological constant vanishes asymptotically for large t !
Weylscaling Weyl scaling : gμν→ (M/χ)2 gμν , φ/M = ln (χ4/V(χ)) Exponential potential : V = M4 exp(-φ/M) No additional constant !
Crossover Quintessence ( like QCD gauge coupling) critical χ where δ grows large critical φ where k grows large k²(φ )=δ(χ)/4 k²(φ )= “1/(2E(φc – φ)/M)” ifj c≈ 276/M ( tuning ! ) Relative increase of dark energy in present cosmological epoch
“Fundamental” Interactions Strong, electromagnetic, weak interactions On astronomical length scales: graviton + cosmon gravitation cosmodynamics
Cosmon • Tiny mass • mc ~ H • New long - range interaction
cosmon mass for standard kinetic term • mc2 = V” for standard exponential potential , k = const. • mc2 = V”/ k2 = V/( k2 M2 ) = 3 Ωh (1 - wh ) H2 /( 2 k2 )
Are fundamental “constants”time dependent ? Fine structure constant α (electric charge) Ratio nucleon mass to Planck mass
“Fifth Force” • Mediated by scalar field • Coupling strength: weaker than gravity ( nonrenormalizable interactions ~ M-2 ) • Composition dependence violation of equivalence principle • Quintessence: connected to time variation of fundamental couplings R.Peccei,J.Sola,C.Wetterich,Phys.Lett.B195,183(1987) C.Wetterich , Nucl.Phys.B302,645(1988)
Quintessence and Time dependence of “fundamental constants” • Fine structure constant depends on value of cosmon field : α(φ) (similar in standard model: couplings depend on value of Higgs scalar field) • Time evolution of φ Time evolution of α Jordan,…
Field dependent gauge coupling( gauge invariance maintained ) for GUT : C.Hill ; Q.Shafi , CW
GUT : running of electromagneticand strong gauge coupling related strong effect from variation of nucleon mass for time dependent couplings ! X.Calmet , H.Fritzsch
Variation of fine structure constant as function of redshift Webb et al Srianand et al
Variation of fine structure constant Three independent data sets from Keck/HIRES Δα/α = - 0.54 (12) 10-5 Murphy,Webb,Flammbaum, june 2003 VLT Δα/α = - 0.06 (6) 10-5 Srianand,Chand,Petitjean,Aracil, feb.2004 z ≈ 2
Crossover quintessence andtime variation of fundamental “constants” Upper bounds for relative variation of the fine structure constant • Oklo natural reactor Δα/α < 10 -7 z=0.13 • Meteorites ( Re-decay ) Δα/α < 3 10 -7 z=0.45 • Crossover Quintessence leads to small variation of couplings at low z as compared to z ≈ 2 !
Time evolution of fundamental couplings traces time evolution of quintessence • todaywh close to -1 : • Small kinetic energy • Slow change of φ • Slow change of α • Very small Δα/αfor low z !
Variation of fine structure constant as function of redshift Webb et al
Cosmon and time variation of couplings • small coupling of cosmon to matter due to fixed points behavior close to fixed point : small time evolution of couplings coupling to matter weaker than gravitational strength
dependence of fixed point on δcould induce observable effect adjusting b6 to reproduce results by Webb et al: smaller for Srianand et al !
Time variation of coupling constants is tiny – would be of very high significance ! Possible signal for Quintessence
Cosmodynamics Cosmon mediates new long-range interaction Range : size of the Universe – horizon Strength : weaker than gravity photon electrodynamics graviton gravity cosmon cosmodynamics Small correction to Newton’s law
Violation of equivalence principle Different couplings of cosmon to proton and neutron Differential acceleration Violation of equivalence principle p,n earth cosmon p,n
Differential acceleration η For unified theories ( GUT ) : η=Δa/2a Q : time dependence of other parameters
Link between time variation of α and violation of equivalence principle typically : η = 10-14 if time variation of α near Oklo upper bound to be tested by MICROSCOPE
Atomic clocks and OKLO assumes that both effects are dominated by change of fine structure constant
Summary • Ωh = 0.7 • Q/Λ : dynamical und static dark energy will be distinguishable • Q : time varying fundamental coupling “constants” violation of equivalence principle
???????????????????????? Why becomes Quintessence dominant in the present cosmological epoch ? Are dark energy and dark matter related ? Can Quintessence be explained in a fundamental unified theory ?
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