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The Backreaction Conjecture to explain Dark Energy. Thomas Buchert , CRALyon. MPIK May 26, 2014. The Standard Model . G = T . t. 2. a ( t ) δij. ?. The Standard Model works !. Baryons ~ 5%. Dark Matter ~ 27%. Dark Energy ~ 68 %. Radiation ~ 0.01%. - PowerPoint PPT Presentation
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The Backreaction Conjectureto explain Dark Energy
Thomas Buchert, CRALyon
MPIK May 26, 2014
The Standard Model
G = T
? a(t) δij 2 t
The Standard Model works ! Baryons
~ 5%
Radiation ~ 0.01%
Dark Energy~ 68 %
Dark Matter
~ 27%
Astier et al. 2006
The Standard Model does not work ! Baryons
~ 5%
Radiation ~ 0.01%
Dark Energy~ 68 %
Dark Matter ~
27%
fundamental scalar field / new particles ?
other laws of gravitation ?
effect of geometricalinhomogeneities ?
backreactionconjecture
Acceleration in the Standard Model
Λa(t) δij 2 t
local acceleration
global acceleration
apparent accelerationa(t) =V (t) ⅓
Generalizing the Standard Model
t
1/3aD= VR
Einstein Spacetime
4g = - dt2 + gij dXi dXj
gijt
a(t)
Averaging Einstein’s Equations
Spatial Average on a compact domain :
Restmass conservation on the domain D
Non - Commutativity
Acceleration Law :
Expansion Law :
Conservation Law :
Integrability :
Kinematical Backreaction
Effective Friedmann Equations
Effective Scalar Field :`Morphon´
Buchert, Larena, Alimi arXiv: gr-qc / 0606020
G = T
m +
Pm + P
m +
Pm + P
=
=
Volume Partitioning
Volume Partitioning
D
M
Volume Partitioning
D
M
D EM= υ
Structure formation and Dark Energy
Roukema, Ostrowski, Buchert arXiv: 1303.4444
Acceleration in the Multiscale Model
Q D
Acceleration in the Multiscale Model
Wiegand, Buchert arXiv: 1002.3912
Average is friedmannian for :
Locally isotropic models (homogeneous) Special LTB models with homogeneous curvature
Integral Properties of Relativistic Models
Average is non-friedmannian :
generic scaling solutions : n = p relativistic perturbation theory : n = p = -1
Unstable Sectors :
Q < 0 and <R> > 0
Q > 0 and <R> < 0
Averaged Cosmologies
Near FRW Cosmologies: Q small
Global Gravitational Instability
Roy, Buchert, Carloni, Obadia arXiv: 1103.1146
Buchert, Larena, Alimi arXiv: gr-qc / 0606020
Phase Space for = 0
Unstable Sectors = 0
DE
DM
Dark Energy Sector = 0
1/aD
Q > 0 and <R> < 0
1/aD
0
21
1/aD
<R>D - 2 ≈ – 6 HD2
QD ≈ 0 <> ≈ 0 :
Volume-dominance of Voids
Sloan Digital Sky Survey - slices
Todai, Tokyo 150000 galaxies
E u c l i d e a n
Observational Strategies
C
log(1+z)
Template Metrics
EuclidLarena, Alimi, Buchert, Kunz, Corasaniti arXiv: 0808.1161
structure formation changes the geometry of the average cosmology
Dark Energy and Dark Matter exist in terms of “curvature energies“ qualitative understanding of the mechanism is completed and it works in the right direction
quantitative understanding in terms of non-perturbative models is in progress reinterpretation of observations !
Conclusions
Further Reading :
arXiv:gr-qc/0001056
0707.21531103.20161112.5335