Quantum Gravity and Inflation

Alexander, S

doi:10.2172/826908

Cited by 2 publications

(2 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…case [31]. It was also found that a truncation to homogeneous cosmology can be made normalizable by making the cosmological constant depend on a physical field and making wavepackets in that field's value [32]. Another approach to the issue is in [33].…”

Section: An Explicit Examplementioning

confidence: 99%

Falsifiable predictions from semiclassical quantum gravity

Smolin¹

2006

Nuclear Physics B

View full text Add to dashboard Cite

Quantum gravity is studied in a semiclassical approximation and it is found that to first order in the Planck length the effect of quantum gravity is to make the low energy effective spacetime metric energy dependent. The diffeomorphism invariance of the semiclassical theory forbids the appearance of a preferred frame of reference, consequently the local symmetry of this energy-dependent effective metric is a non-linear realization of the Lorentz transformations, which renders the Planck energy observer independent. This gives a form of deformed or doubly special relativity (DSR), previously explored with Magueijo, called the rainbow metric. The general argument determines the sign, but not the exact coefficient of the effect. But it applies in all dimensions with and without supersymmetry, and is, at least to leading order, universal for all matter couplings. A consequence of DSR realized with an energy dependent effective metric is a helicity independent energy dependence in the speed of light to first order in the Planck length. However, thresholds for Tev photons and GZK protons are unchanged from special relativistic predictions. These predictions of quantum gravity are falsifiable by the upcoming AUGER and GLAST experiments.Comment: 9 page

show abstract

Section: An Explicit Examplementioning

confidence: 99%

Falsifiable predictions from semiclassical quantum gravity

Smolin¹

2006

Nuclear Physics B

View full text Add to dashboard Cite

show abstract

“…Another approach to inflation within loop quantum gravity is given in [119]. Exact homogeneous quantum states can be constructed for general relativity coupled to a scalar field with an arbitrary potential.…”

mentioning

confidence: 99%

An Invitation to Loop Quantum Gravity

Smolin¹

2004

Quantum Theory and Symmetries

135

207

View full text Add to dashboard Cite

We describe the basic assumptions and key results of loop quantum gravity, which is a background independent approach to quantum gravity. The emphasis is on the basic physical principles and how one deduces predictions from them, at a level suitable for physicists in other areas such as string theory, cosmology, particle physics, astrophysics and condensed matter physics. No details are given, but references are provided to guide the interested reader to the literature. The present state of knowledge is summarized in a list of 42 key results on topics including the hamiltonian and path integral quantizations, coupling to matter, approaches to unification, extensions to supergravity and higher dimensional theories, as well as applications to black holes, cosmology and Plank scale phenomenology. We describe the near term prospects for observational tests of quantum theories of gravity and the expectations that loop quantum gravity may provide predictions for their outcomes. Finally, we provide answers to frequently asked questions and a list of key open problems.

show abstract

Quantum Gravity and Inflation

Cited by 2 publications

References 10 publications

Falsifiable predictions from semiclassical quantum gravity

Falsifiable predictions from semiclassical quantum gravity

An Invitation to Loop Quantum Gravity

Contact Info

Product

Resources

About