Results 31 to 40 of about 17,519 (197)

Kinetic Inflation in Stringy and Other Cosmologies [PDF]

, 1994
An inflationary epoch driven by the kinetic energy density in a dynamical Planck mass is studied. In the conformally related Einstein frame it is easiest to see the demands of successful inflation cannot be satisfied by kinetic inflation alone. Viewed in
A.H. Guth, C. Brans, G. Veneziano, J.J. Levin, J.J. Levin, J.J. Levin, Janna J. Levin, M. Gasperini, M. Gasperini, P. Jordan, P.G. Bergmann, R. Brustein, R. Brustein, R.H. Dicke, R.V. Wagoner, Y. Hu   +15 more
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Non-parametric reconstruction of an inflaton potential from Einstein–Cartan–Sciama–Kibble gravity with particle production

Physics Letters B, 2016
The coupling between spin and torsion in the Einstein–Cartan–Sciama–Kibble theory of gravity generates gravitational repulsion at very high densities, which prevents a singularity in a black hole and may create there a new universe.
Shantanu Desai, Nikodem J. Popławski
doaj   +1 more source

The Cosmological Slingshot Scenario: a Stringy Proposal for the Early Time Cosmology [PDF]

, 2008
In the Cosmological Slingshot Scenario, our Universe is a D3-brane that extends in the 4d noncompact directions of a warped Calabi-Yau compactification of IIB Supergravity.
Alex Kehagias, Carmen Núñez, Cristiano Germani, José D. Edelstein, Martin Schvellinger, Nicolás Grandi, Nicolás Grandi   +6 more
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Dark Energy: The Shadowy Reflection of Dark Matter?

Entropy, 2016
In this article, we review a series of recent theoretical results regarding a conventional approach to the dark energy (DE) concept. This approach is distinguished among others for its simplicity and its physical relevance.
Kostas Kleidis, Nikolaos K. Spyrou
doaj   +1 more source

Variable-Speed-of-Light Cosmology from Brane World Scenario [PDF]

, 2001
We argue that the four-dimensional universe on the TeV brane of the Randall-Sundrum scenario takes the bimetric structure of Clayton and Moffat, with gravitons traveling faster than photons instead, while the radion varies with time.
A. Albrecht, A. Albrecht, A.D. Linde, A.H. Guth, B.A. Bassett, C. Csaki, C. Csaki, D. Youm, D.H. Coule, D.J. Chung, Donam Youm, E. Kiritsis, G. Kalbermann, H. Ishihara, J. Lykken, J.D. Barrow, J.D. Barrow, J.D. Barrow, J.D. Barrow, J.D. Barrow, J.D. Bekenstein, J.K. Webb, J.K. Webb, J.M. Cline, J.W. Moffat, L. Bergstrom, L. Randall, L. Randall, M. Kaplinghat, M.A. Clayton, M.A. Clayton, M.A. Clayton, M.K. Mak, N. Arkani-Hamed, P.P. Avelino, R.A. Battye, S. Kachru, S. Liberati, S.H. Alexander, T. Harko, W.D. Goldberger, W.D. Goldberger   +41 more
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Can Typicality Arguments Dissolve Cosmology’s Flatness Problem? [PDF]

Philosophy of Science, 2017
Several physicists, among them Hawking, Page, Coule, and Carroll, have argued against the probabilistic intuitions underlying fine-tuning arguments in cosmology and instead propose that the canonical measure on the phase space of Friedman-Robertson-Walker space-times should be used to evaluate fine-tuning.
openaire   +2 more sources

A solution to the anisotropy problem in bouncing cosmologies [PDF]

, 2009
Bouncing cosmologies are often proposed as alternatives to standard inflation for the explanation of the homogeneity and flatness of the universe. In such scenarios, the present cosmological expansion is preceded by a contraction phase.
Bozza, V., Bruni, M.
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Cosmology with Ricci-Flat Compactification [PDF]

Progress of Theoretical Physics Supplement, 1986
La limite theorie du champ des theories de supercorde a 10 dimensions suggere une compactification sur des varietes de Calabi-Yau Ricci-plate a 6 dimensions.
openaire   +1 more source

Brane-World Cosmology, Bulk Scalars and Perturbations [PDF]

, 2001
We investigate aspects of cosmology in brane world theories with a bulk scalar field. We concentrate on a recent model motivated from supergravity in singular spaces.
Brax, P., Davis, A. C., van de Bruck, C.
core   +3 more sources

A time varying speed of light as a solution to cosmological puzzles [PDF]

, 1999
We consider the cosmological implications of light travelling faster in the early Universe. We propose a prescription for deriving corrections to the cosmological evolution equations while the speed of light $c$ is changing. We then show how the horizon,
A. Albrecht, A. Guth, A. Guth, A. Linde, A. Linde, A. Starobinsky, A. Vilenkin, Andreas Albrecht, C. M. Will, H. Kodama, J. Bardeen, J. Barrow, J. Barrow, J. D. Bekenstein, J. D. Bekenstein, J. E. Solheim, J. Levin, J. Levin, J. Levin, J. Moffat, J. Moffat, J. Peebles, João Magueijo, P. Steinhardt, R. H. Dicke, S. W. Hawking, T. Kibble, V. Mukhanov, V. Mukhanov, W. A. Baum, Y. Hu   +30 more
core   +2 more sources