Liouville Cosmology

Ellis, John; Mavromatos, Nikolaos; Nanopoulos, Dimitri V.

doi:10.1007/3-540-26373-x_32

Cited by 82 publications

(187 citation statements)

References 23 publications

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“…These theories may be understood as non-linear realizations of the Lorentz group [4], in which modified Lorentz transformations reduce to the usual ones at low energies, but leave invariant E P , the borderline between classical and quantum gravity. These theories can explain the recent claims for high-energy cosmic ray anomalies [5][6][7]4] (see also [8][9][10]). This is due to the introduction of deformed dispersion relations (i.e.…”

Section: Introductionmentioning

confidence: 80%

Nonlinear relativity in position space

2004

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We propose two methods for obtaining the position space of non-linear relativity, i.e. the dual of its usual momentum space formulation. In the first approach we require that plane waves still be solutions to free field theory. This is equivalent to postulating the invariance of the linear contraction between position and momentum spaces, and dictates a set of energy-dependent spacetime Lorentz transformations. In turn this leads to an energy dependent metric. The second, more problematic approach allows for the position space to acquire a non-linear representation of the Lorentz group independently of the chosen representation in momentum space. This requires a non-linear contraction between momentum and position spaces. We discuss a variety of physical implications of these approaches and show how they point to two rather distinct formulations of theories of gravity with an invariant energy and/or length scale.

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Section: Introductionmentioning

confidence: 80%

Nonlinear relativity in position space

2004

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“…As discussed in [59], such features lead to important deviations from the (specific) Lindblad evolutionary form. which, in turn implies the possibility of significant enhancement of the effects: the latter can be as large as (29), thereby offering the possibility of experimental tests in the next-generation of neutral-kaon (or other meson) experiments [52,53], as well as future neutrino facilities [61].…”

Section: Terrestrial Experiments On Space-time Foammentioning

confidence: 98%

“…However, in our Liouville-string case, which is the basis of the present model of quantum gravity foam, the deviations from the conventional quantum mechanical evolution in the respective density matrix are non linear [7,59]. In such a case, the parameters α, β, γ can only be viewed as appropriate averages, which themselves depend on the wave-functional of the system.…”

Section: Terrestrial Experiments On Space-time Foammentioning

confidence: 99%

Testing a (Stringy) Model of Quantum Gravity

Mavromatos

2001

Dark Matter in Astro- And Particle Physics

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Abstract. I discuss a specific model of space-time foam, inspired by the modern nonperturbative approach to string theory (D-branes). The model views our world as a three brane, intersecting with D-particles that represent stringy quantum gravity effects, which can be real or virtual. In this picture, matter is represented generically by (closed or open) strings on the D3 brane propagating in such a background. Scattering of the (matter) strings off the D-particles causes recoil of the latter, which in turn results in a distortion of the surrounding space-time fluid and the formation of (microscopic, i.e. Planckian size) horizons around the defects. As a mean-field result, the dispersion relation of the various particle excitations is modified, leading to non-trivial optical properties of the space time, for instance a non-trivial refractive index for the case of photons or other massless probes. Such models make falsifiable predictions, that may be tested experimentally in the foreseeable future. I describe a few such tests, ranging from observations of light from distant gamma-ray-bursters and ultra high energy cosmic rays, to tests using gravity-wave interferometric devices and terrestrial particle physics experiments involving, for instance, neutral kaons.

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“…By comparing the content of the first estimates l produced in this research line [98] with the understanding that emerged from follow-up studies [99,100,101,102,85,103] one can l Ref. [98] is at this point obsolete, since the relevant manuscript has been revised for the published version [100] and the recent Ref.…”

Section: Derivation Of Limits From Analysis Of Synchrotron Radiationmentioning

confidence: 99%

Introduction to Quantum-Gravity Phenomenology

Amelino‐Camelia

2005

Planck Scale Effects in Astrophysics and Cosmology

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After a brief review of the first phase of development of Quantum-Gravity Phenomenology, I argue that this research line is now ready to enter a more advanced phase: while at first it was legitimate to resort to heuristic order-of-magnitude estimates, which were sufficient to establish that sensitivity to Planck-scale effects can be achieved, we should now rely on detailed analyses of some reference test theories. I illustrate this point in the specific example of studies of Planck-scale modifications of the energy/momentum dispersion relation, for which I consider two test theories. Both the photon-stability analyses and the Crab-nebula synchrotron-radiation analyses, which had raised high hopes of "beyond-Plankian" experimental bounds, turn out to be rather ineffective in constraining the two test theories. Examples of analyses which can provide constraints of rather wide applicability are the so-called "time-of-flight analyses", in the context of observations of gamma-ray bursts, and the analyses of the cosmic-ray spectrum near the GZK scale.

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Liouville Cosmology

Cited by 82 publications

References 23 publications

Nonlinear relativity in position space

Nonlinear relativity in position space

Testing a (Stringy) Model of Quantum Gravity

Introduction to Quantum-Gravity Phenomenology

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