G B Tupper UCT Zwicky (1933) 1970’s: Galactic Rotation Curves + Standard Model of Particle Physics Beyond SMPP : Dark Matter or Modified Newtonian Dynamics (MOND) ? o Milgrom (1983)[1] Modify inertia, minimum acceleration a F a a 0 x x 1 x a0 a0 H 0 DE o Bekenstein & Milgrom (1984)[2] Keep a Modify Poisson equation 4GN a0 S MOND x x x x 2 d 3 x 2 8GN a0 2 2 2 2 x 2 2 x x 1 2 ln 1 x x 1 x x 2 x, x 1 3 Bekenstein (2004)[3] : TeVeS Bimetric theory g e2 g~ 2 sinh 2 A A Matter frame Tensor g ~ g Einstein-Hilbert ~ Constrained Vector A A g 1 Scalar 2 Zlosnik et al (2006): constraint e A A Zlosnik et al (2006)[4]: Nonlinear Aether MOND One metric g Timelike vector A Action c1 1 c3 , c2 0 S S EH S A Smatter S A d 4 x g 4ao2 ln 1 A A 1 F F 2a 2 0 Newtonian E , B 0 1 A 2 3 32 Milgrom Bimetric (2009)[5] Bekenstein & Milgrom (1984)[2] 2 2 S MOND d 3 x 2 8GN a0 “like nonlinear electrodynamics and QCD.” Pagels & Tomboulis (1978)[6]: quantum field theory, renormalization breaks conformal invariance ; effective action 1 F F g3 dg 3 F F t ln QCDeff 4 2 4 QCD g3 g 3 4 g 3 t Asymptotic freedom g 3 bg 33 small g Infrared slavery, confinement Linear potential QED QCD flux tube g3 g3 3 3 bg Interpolate g 3 2 1 bg 3 1 F F ln 2 4QCD 1 ln g 2 bg 2 Large field weak coupling small field strong coupling IR QCDeff 4QCD F F 4 4QCD 3 2 QCD Gluons self interact Renormalizable Asymptotically free Local gauge invariance GRAVITY Broken scale invariance, effective action Gravitons self interact Nonrenormalizable, effeftive field theory [7] Asymptotically safe [8] General coordinate invariance ?? “Dielectric Infrared Modified Nonlinear Dynamics” Require o Pure gravity o Reduce to General Relativity for ‘strong fields’ o Natural MONDian limit for weak fields 2 not f as Ricci Note GR has General Coordinate Invariance and Local Lorentz Invariance m Fermions (matter) require tetrad field e g e e mn m n GR has hidden LLI Christoffel connection torsionless T 0 Weitzenbock connection ea ea, nonzero torsion T 0 zero curvature 0 Weitzenbock spacetime: absolute parallelism K Contorsion tensor Denote Up to a “surface term” S EH K K g (K K K K ) 1 1 4 4 d x g d xeK K 16GN 16GN “Teleparallel equivalent of GR” K K Is GCI scalar but LLT K K 4 divergence 0 Hypothesis: (infrared ) effects in quantum gravity break LLI (like conformal invariance in QCD) but preserve GCI (like gauge invariance in QCD) Propose effective action: K K 1 4 S DIMOND d xeK K 2 16GN 2a0 GR limit automatic Newtonian MOND limit automatic Is DIMOND ‘beautiful’ ? Can one derive breaking of LLI and so effective action? What about cosmology – especially ‘dark energy’ ? [10] [1]M Milgrom, Astrophys J 270(1983)365,371,384. [2]J Bekenstein and M Milgrom, Astrophys J 286(1984)7. [3]J D Bekenstein, Phys Rev D70(2004)083509. [4]T G Zlosnik, P G Ferreira and G D Starkman, Phys Rev D75(2007)044017. [5]M Milgrom, Phys Rev D80(2009)123536. [6]H Pagels and E Tomboulis, Nucl Phys 143(1978)485. [7] J F Donoghue. Phys Rev D50(1994)3874. [8] M Reuter, Phys Rev D57(1998)971. [9]H I Arcos and J G Pereira, Int J Mod Phys D13(2004)2193. [10]G R Bengochea and R Ferraro, Phys Rev D79(2009)124019.