Frdric HenryCouannier

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GR limits and alternatives

• Frédéric Henry-Couannier
• CPPM/RENOIR Marseille
• www.darksideofgravity.com

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The essential intuition
Science is possible It is possible,
through a chain of reasonings and computations,
to derive and understand in a qualitative and
quantitative way an extreme variety of
observational facts (all?) starting from a
restricted set of invariant principles (a single
not arbitrary one ?) and fundamental
constants. ? A theory must be
coherent and should agree with experiments but
also be predictive hence falsifiable

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The essential intuition

• Main reason for taking it serious extremely
  improbable a priori, the intuition was confirmed
  many times, leading to spectacular breakthroughs
  and progresses of our knowledge and technology.
• To give it up to be satisfied with a purely
  descriptive attitude which amounts to introduce
  ad hoc new combinations of ideas and free
  parameters, the epicycles, to deal with the
  successively encountered anomalies.
• This way of doing science reveals major
  pathologies of our theoretical frameworks
  principles not enough constraining or producing
  incalculability.

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GR from principles to equations

• Science is possible
• Space-time is differentiable
• SM action(g1?? -, A???)?
• Extreme Action Principle
• 1.? General Covariance 2. ?
  
• 3. ? GR
  Action
• 4. ? Einstein
  Equations

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GR From the Equations to Gravity

• The g?? field does not only stand for a
  pseudo-force, it correctly describes a genuine
  interaction gravity.
• g?? is identified with the metric of space-time
• ? g?? very different from usual fields
  describes geometry, deformations, curvature of
  space-time which now is dynamical.
• Various forms of the equivalence principle are
  valid and can be tested

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GR

• The successes
• Conceptually very beautiful and the triumph of
  symmetry
• Successfully tested ( with flying colors ) in
  many sectorrs of gravity
• The limits ?
• Exact calculus impossible in general,
  approximative calculus extremely difficult in
  practice
• Not predictive in cosmology without the help of
  the strong cosmological principle
• Well known incompatibility with Quantum Mechanics
• Elimination by hand of an infinite number of
  allowed terms ?? Gauss-Bonnet, Powers of
  curvature

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GR Many sectors still not tested

• The PostPostNewtonien domain
• Pressure as a source for gravity
• The black hole horizon
• Gravito-magnetism
• Gravitational waves (polarisation, speed)?

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Anomalies ?

• Locally the Pioneer effect ?
• Globally cosmology ?
• PN tests of gravity dont tell us that GR is
  valid in the cosmological domain !
• GR without Cosmological Principle is not
  predictive the Cosmological Principle is not
  valid for a spherical empty bubble cut out of the
  homogeneous expanding universe
• GR Cosmological Principle Dark matter
  Inflation Dark energy epicyclic construction
  whatever its successes !
• - Ad hoc and enigmatic components
• - Free parameters
• - Many residual anomalies lithium, CMB
  anisotropies ?
• - Anyway, it is only by chance that any
  construction based upon GR Cosmological
  Principle can be successful

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Alternative theories

• All theories directly confronted with various
  tests (tensor-scalar and other effective theories
  motivated by super-strings at low energy) are
  still built in an epicyclic characteristic way
  which consists in introducing additional terms
  in the actions with their associate coupling
  constants.
• Landscape of theories at fundamental and
  effective levels!
• Is this science ?

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Another way ?

• If g???is just a field like any other one,
  space-time is flat and non dynamical with
  background metric ??? Riem ????0
• Fashionable theories in the seventies (Rosen,
  Rastall, Ni, Belinfante)?
• Theories explicitely introducing ??? in the
  action
• Theories seriously violating the strong
  equivalence principle ? excluded by tests

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Given the background the gravitational field has
two sides!
andmust be treated in a symmetrical way in the
action!
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Equations of DGGR with background

• New equations

Extremize action eliminate
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DG gravity with its dark side Our
Standard Model lives in The other side
Standard Model lives in ? invisible world
from our side point of view Two gravities are
linked (We shall check that the connexion is
anti-gravitational between the 2 worlds)
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Two forms of g??for a complete and correct
description of gravity

• Isotropic form
• Two possible forms
• et

Cosmology GW
Gravity Pioneer
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DG

• Even more symmetry
• PN tests of gravity OK
• Pioneer effect completely explained
• Calculus always trivial
• Predictivity in cosmology
• Compatible with Quantum Mecanics
• No other free parameter than G (?)??

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DG must rehabilitate global symmetries of
space-time

• Flat space-time with metric ?
• Lorentz-Poincaré Global Invariance ? Noether
  currents
• Space-time Discrete Global symmetries and  bad
  representations of the Lorentz group
  rehabilitation( negative energies, tachyons)?
• All DG solutions indeed satisfy

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Form Invariance (?isommetry)?
In the frame where-
Form Invariance of under spatial
coordinate perrmutations- Form Invariance of
under rotations
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Interpretation of g?? diag(B,A,A,A)
g?? does not describe space and time
deformations but variations of local
speed of light and caracteristic times from the
point of view of an exterior (out of gravity)
observer !
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X form symmetry(I)?

• Most general form of the complex field
• A1 ? symmetry X OK
• 
  ? BA
• A?1, C1 ? symmetry X restored by
• 
  ? B1/A

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X form Symmetry (II)?

• If C ?1, Ai ? X symmetry X restored by
  
• ? B -A

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X form Symmetry (III)?
If A ? i and ? 1, C?1 violates the X form
symmetry and the introduction of
is not a solution. Conclusion BA or
B1/A and Moreover, requiring that the solutions
satisfy this symmetry must determine the coupling
constants associated with all other allowed
terms in the action !
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GR

• The successes
• Conceptually beautiful and the triumph of
  symmetry
• Successfully tested ( with flying colors ) in
  many sectors of gravity
• The limits ?
• Exact calculus impossible in general,
  approximative calculus extremely difficult in
  practice
• Not predictive in cosmology without the strong
  cosmological principle
• Well known Incompatibility with Quantum Mechanics
• Elimination by hand of an infinite number of
  allowed terms ?? Gauss-Bonnet, Powers of
  curvature

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DG

• Even more symmetry (global, continuous or
  discretes)?
• PN tests of gravity OK
• Pioneer effect completely understood
• Calculus always trivial
• Predictivity in cosmology
• Compatible with Quantum Mechanics
• No other free parameter than G??

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B-A , the cosmological background

• 2 sides of gravity homogeneous and isotropic ?
  spatially flat gravities
• Vanishing Source (exact compensation)
• ? symmetries completely determine the
  evolution of B(t)-A(t)

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Time reversal
Standard Understanding Reversing time Going
backward in time
t
Universe a2(t)(dt2-d?2)?
Dark Gravity Reversing time Jumping into
hidden face of universe
a-1(t)?
a(t) t 2
1
a(t)e-t
a(t) t -2
t ? 8
- 8???t
t0 Big Bang
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Cosmology B(t)-A(t)?

• 3 solutions ? discontinuities !?
• Time reversal Symmetry verified because
  a(t)1/a(-t)?
• No time reversal paradox
• No singularity at t0
• A(t) only affects matter, not photons

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The Pioneer effect

• Facts an abnormal blue-shift of radiowave
  signal received from Pioneer spacecrafts from 20
  to 70 U.A
• Possible Interpretations
• A clock drift in time Pioneer / earth
• An abnormal constant deceleration directed toward
  the sun
• All systematical effects eliminated.

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The Pioneer effect
A discontinuity between 10 and 15 U.A ?
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The Pioneer effect
A discontinuity between 10 and 15 U.A !
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The Pioneer effect
- A discontinuity between 10 and 15 U.A in 1983
! - The discontinuity propagates toward us,
reached Jupiter in 1997, will reach earth 2100
!!- A discontinuity detected by New Horizons at
0.4 UA from Jupiter !!!
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Here it is !
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The Pioneer effect and GR

• No rigorous treatment of the influence of an
  expanding background on local dynamics.
• Best effort the Mc Vittie solution
• r?ra(t)r ? negligible acceleration effect due
  to expansion in g0r

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Other DG predictions

• Longitudinal  gravitational  waves
• Other PPN parameters, no Black Hole
• No frame-dragging, pressure and gravity dont
  source gravity
• All kinds of discontinuity effects

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Conclusion

• DG the other option of a binary choice at the
  level of the conceptual
• foundations of GR
• DG OK with all PN tests, explains Pioneer effect
  and very predictive
• in all sectors of gravity
• DG is a genuine theory, i.e. has no epicycles.
• A theoretical and observational program to
  study the various discontinuity effects will be
  necessary before being able to study cosmology

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Metrics in GR vs DG

• The metric is the object one must use to raise
  and lower indices on any tensor field
• RG is the metric ?
• GR is the theory of
• DG is the metric ?
• DG is the theory of gravity with two dependent
  sides and

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Local Gravity

• As in the bi-metric theory of JP Petit
• Objects living on the same side of gravity
  attract each other
• Objects living on different sides of gravity
  reppel each other

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Local Gravity
DG RG (Schwarzschild)?