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- Simon M. Poulding, Robert Alexander, John A. Clark, Mark J. Hadley
- GECCO
- 2013

The effectiveness of probabilistic structural testing depends on the characteristics of the probability distribution from which test inputs are sampled at random. Metaheuristic search has been shown to be a practical method of optimising the characteristics of such distributions. However, the applicability of the existing search-based algorithm is limited… (More)

- Mark J Hadley
- 2000

It is shown that models of elementary particles in classical general relativity will naturally have the transformation properties of a spinor if the spacetime manifold is not time orientable. From a purely pragmatic interpretation of quantum theory this explains why spinors are needed to represent particles. The models are based entirely on classical… (More)

- Mark J Hadley
- 2000

Contrary to established beliefs, spacetime may not be time-orientable. By considering an experimental test of time orientability it is shown that a failure of time-orientability of a spacetime region would be indistinguishable from a particle antiparticle annihilation event.

- Mark J Hadley
- 1997

For the first time it is shown that the logic of quantum mechanics can be derived from Classical Physics. An orthomodular lattice of propositions , characteristic of quantum logic, is constructed for manifolds in Einstein's theory of general relativity. A particle is modelled by a topo-logically non-trivial 4-manifold with closed timelike curves-a 4-geon,… (More)

- Mark J Hadley
- 1999

A new class of electrically charged wormholes is described in which the outer two sphere is not spanned by a compact coorientable hypersurface. These wormholes can therefore display net electric charge from the source free Maxwell's equation. This extends the work of Sorkin on non-space orientable manifolds, to spacetimes which do not admit a time… (More)

- Mark J. Hadley
- 2007

It has been shown by Hadley that the logic of quantum mechanics is consistent with general relativity when closed time-like curves are permitted. This is done by hypothesising particles as 4-geons: particle-like solutions to Einstein's field equations with closed time-like curves. Hadley provides axioms that need to be satisfied for quantum logic to be… (More)

- Mark J Hadley
- 2006

There is a deep structural link between acausal spacetimes and quantum theory. As a consequence quantum theory may resolve some " paradoxes " of time travel. Conversely, non-time-orientable spacetimes naturally give rise to electric charges and spin half. If an explanation of quantum theory is possible, then general relativity with time travel could be it.

- Mark J Hadley
- 2007

Classical particle-like solutions of field equations such as general relativity, could account for dark matter. Such particles would not interact quantum mechanically and would have negligible interactions apart from gravitation. As a relic from the big bang, they would be a candidate for cold dark matter consistent with observations.

- Mark J Hadley
- 2007

Spacetime manifolds that are not time orientable play a key role in a gravitational explanation of quantum theory. Such manifolds allow topology change, but also have fascinating additional properties such as net charge from source-free equations and spin half transformation properties. It is shown how the logical structure of propositions and the… (More)

- Mark J Hadley
- 1999

The non-classical features of quantum mechanics are reproduced using models constructed with a classical theory-general relativity. The inability to define complete initial data consistently and independently of future measurements, non-locality, and the non-Boolean logical structure are reproduced by these examples. The key feature of the models is the… (More)