Mark.hadley@warwick.ac.uk Welcome to GT5 Wormholes Time machines and Energy conditions Chairperson...

mark.hadley@warwick.ac.uk

Welcome to GT5

Wormholes Time machines and Energy conditions

Chairperson Dr. Mark Hadley

MG11 Berlin

GT5 Schedule

Hadley, Mark Time Machines and Quantum Theory 14.30 25'

Krasnikov, Serguei Mundane Wormholes 14.55 25'

Lobo, Francisco Traversable wormholes supported by cosmic accelerated expanding equations of state15.20 25'

Gonzalez-diaz, Pedro F.Wormholes in the accelerating Universe 15.45 25'

Adamiak, Jaroslaw Static and Dynamic Traversable Wormholes 16.10 20'

Tea Break

De Felice, Fernando Naked Singularities, time machines and impulsive events17.00 15'

Mitskievich, Nikolai V. Nariai--Bertotti--Robinson spacetimes as a building material for one-way wormholes with horizons, but without singularity17.15 15'

Darabi, Farhad Classical and quantum wormholes in a λ-decaying cosmology17.30 15'

Zannias, Thomas On Wormholes solutions of Einstein-Masless K-Theory.17.45 15'

Garattini, Remo Self sustained traversable wormholes? 18.00 15'

Zaslavskii, Oleg N-spheres: regular black holes without apparent horizons, static wormholes with event horizons and gravastars with a tube-like core18.15 15'

Osterbrink, Lutz Averaged Energy Inequalities for Non-Minimally Coupled Classical Scalar Fields18.30 15'

Berrocal Arellano, Dynamic wormhole spacetimes coupled to nonlinear 18.45 15' Aaron Vicente

mark.hadley@warwick.ac.uk

Would Einstein have come to this session?

GT5

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Einstein

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1950

=

χ

Causality cannot be violated

Bell’s Inequalities 1963

Aspect’s Experiments

1983 --------------

GT5

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2006

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Einstein

=

God goes not play dice

√

Dr Mark Hadley

Time machines and quantum theory

mark.hadley@warwick.ac.uk

Explaining Quantum Theory

• Bell’s Inequalities

• Aspect’s EPR Experiments

We cannot explain quantum theory with any local hidden variables theory.

We cannot model particles as 3-D solutions [of GR] that evolve in time.

mark.hadley@warwick.ac.uk

Evolving 3-manifolds…

• Prepare a beam of electrons

Stern Gerlach

X

Y

mark.hadley@warwick.ac.uk

Spin measurement• Venn diagram of all 3-manifolds

X↑

X↓

Y←Y→

X↑ Y→

X↓ Y→ X↓ Y←

X↑ Y←

All manifolds consistent with the state preparation

X↑ Y→

X↓ Y→ X↓ Y←

X↑ Y←

but, {X↑ Y→} does not exist in theory or experiment.

mark.hadley@warwick.ac.uk

Geometric models

• We cannot model particles as 3-D solutions that evolve in time.

• Need context dependence/ Non-locality

• Non-trivial causal structure as part of a particle: 4-geon

mark.hadley@warwick.ac.uk

Spin measurement

{X↑∩ Y→} = ∅√

X↑

X↓ Y←

Y→

State preparation

x-measurement y-measurement

Sets of 3 manifolds

Incompatible boundary conditions

mark.hadley@warwick.ac.uk

Quantum Logic• Quantum theory is characterised by an

orthomodular lattice of propositions – a non-Boolean logic.

• so is GR with a acausal space times.

• The only known way to represent experimental probabilities on such a lattice is using subspaces of a Hilbert space.

mark.hadley@warwick.ac.uk

Testing the orientability of space

mark.hadley@warwick.ac.uk

Testing the orientability of time ?

mark.hadley@warwick.ac.uk

Testing the orientability of time

mark.hadley@warwick.ac.uk

Acausal manifoldsMathematical and physical descriptions of a space time are not the same

• Space-time

+ The observer

+ The experiments

+ The results..

..are all interlinked

Quantum theory gives a consistent description of such an interlinking.

mark.hadley@warwick.ac.uk

GR may be the unifying theory

after all

mark.hadley@warwick.ac.uk

Einstein Rosen Bridgeis not time-orientable

Einstein Rosen bridge: Phys Rev 48, 73 (1935)

mark.hadley@warwick.ac.uk

Other results from non time-orientable manifolds

• Electric, but not magnetic chare from source-free Einstein-Maxwell equations

• Diemer and Hadley Class. Quantum Grav. (1999)

• Explains spin half• Hadley Class. Quantum Grav. (2000)

mark.hadley@warwick.ac.uk

4-geon• Non-trivial causal structure as part of the

particle.• Particle and its evolution are inseparable.

• Context dependent– Signals from the “future” experimental set up.– Measurement can set non-redundant boundary

conditions

(Time reversal is part of a measurement)

mark.hadley@warwick.ac.uk

A gravitational explanation for quantum theory

• Aims to explain– QM– Particle spectrum– Fundamental interactions

• Predictions– No graviton (Gravity waves are just classical waves)

– Spin-half

–Parity is conserved