1. The Strained State Cosmology Angelo Tartaglia Politecnico di Torino and INFN

2. 2 “Elastic” continua xμxμ XaXa ξaξa r r’ N+n N N April 19 2011 PONT-2011 Avignon

3. 3 Space-time defect Flat reference frame Curved natural frame April 19 2011 PONT-2011 Avignon

4. 4 Strained space-time dr 0 dr unstrained strained  gg Strain tensor April 19 2011 PONT-2011 Avignon

5. 5 Physical relevance of the strain In a continuum, strain is associated with stress Strain and stress correspond to a deformation energy Defects can fix the global symmetry Strain is originated by the presence of matter/energy or by defects April 19 2011 PONT-2011 Avignon

6. 6 Isotropic medium Lamé coefficients April 19 2011 PONT-2011 Avignon Elastic energy

7. 7 The Lagrangian density “Kinetic” term Potential term Geometry April 19 2011 PONT-2011 Avignon

8. 8 Robertson-Walker symmetry z r r l l   =f(r) April 19 2011 PONT-2011 Avignon

9. September 6, 2010ERE2010 - Granada 9 The Hubble parameter A. Tartaglia and N. Radicella, CQG, 27, 035001 (2010)

10. 10 10 Fitting the data (307 SnIa) April 19 2011 PONT-2011 Avignon

11. September 6, 2010ERE2010 - Granada 11 Other cosmological tests Primordial nucleosynthesis (correct proportion between He, D and hydrogen) CMB spectrum Structure formation after the recombination era.

12. 12 Bayesian posterior probability April 19 2011 PONT-2011 Avignon

13. 13 Optimal value of the parameters N. Radicella, M. Sereno, A. Tartaglia, IJMPD, 20, n. 3 (2011) April 19 2011 PONT-2011 Avignon

14. 14 Schwarzschild symmetry Natural frame Reference frame (Minkowski) Gauge function April 19 2011 PONT-2011 Avignon

15. 15 The strain tensor

16. 16 Weak strain April 19 2011 PONT-2011 Avignon

17. 17 Approximate solutions ,  = functions of,  ~,  April 19 2011 PONT-2011 Avignon

18. 18 Post-Keplerian circular orbits Looks like the effect of dark matter Light rays April 19 2011 PONT-2011 Avignon

19. 19 Conclusion The strained space-time theory introduces a strain energy of vacuum depending on curvature The theory accounts for the accelerated expansion of the universe and is consistent with BBN, structure formation and SnIa’s The strain affects free fall also in spherically symmetric stationary space- times April 19 2011 PONT-2011 Avignon

20. References A. Tartaglia and N. Radicella, CQG, 27, 035001 (2010) N. Radicella, M. Sereno, A. Tartaglia, IJMPD, 20, n. 3 (in press) 2011