the Cosmological Constant Problem

Roland TRIAYCentre de Physique Théorique CNRS

Université de Provence

Int. Journ. Mod. Phys. D 14,10,1667 (2005)

Nonlinear Cosmological Workshop - NCP (2006) Nice

the Cosmological Constant

• Observations• Geometrical Status• Modeling Gravitational Structures

“Einstein’s biggest blunder”Prelude

Observations - the 80thIn the past :•Dynamics of galaxies in clusters•Minimum age of the Universe

In the 80’s:Hubble diagram (QSOs, BCGs), VLSS (QSOs)(spatially) closed Universe

Observations - Nowadays

Nowadays : CMB temperature fluctuationsHubble diagram (SuperNovæ)

Observations-SNa

A.G. Riess etal astro-ph/0402512

Observations - Nowadays

A.V Filippenko astro-ph/0410609

Face to the -Problem

« The  Cosmological Constant From the Viewpoint of String Th. » E. Witten 2000« The  Cosmological Constant Problems » S. Weinberg 2000« The  Cosmological Constant » S. Carrol 2000« The Case for a Positive Cosmological -term » V. Sahni, A. Starobinsky 2000« The  Cosmological Constant and Dark Energy » P.J.E. Peebles, B. Ratra 2002« On the Casimir Energy Contribution to the Obs. Value of … » I.O Cherednikov 2002« The  Cosmological Constant Problem » J. W. Moffat 2003« Cosmological Constant Weight of the Vacuum » T. Padmanabham 2003…

Status of - Geometry)

The gravitational field and its sources are characterized by

Schwarzschild solution - Newton approximation

Dimensional analysis of EE

Modeling gravitational structures

With : Gravitation becomes repulsive at “large” scale•No -effect in Solar neighborhood•Small effect in the outerpart of the Galaxy•Intervenes at the edge of LSC •Homogeneity scale

(Modified) Newton law

The cosmological Constant Problem

The contribution of quantum fluctuations

A similar problem happens when one assumes•Solar neighborhood•Primordial epoch ( Vacuum dominate expansion)

Another version of the Cosmological Constant Problem

Understanding the acceleration of the cosmological expansion

Rescaling !!!

Understanding Quantum Gravity !!!