The energy density of ``wound" fields in a toroidal universe
TLDR
In this paper, the authors show that the universe has a toroidal topology with wound scalar fields around its cycles, which can contribute significantly to the total energy density of the universe.Abstract:
The observational limits on the present energy density of the Universe allow for a component that redshifts like 1/a2 and can contribute significantly to the total. We show that a possible origin for such a contribution is that the universe has a toroidal topology with ``wound" scalar fields around its cycles.read more
Citations
More filters
The White Dwarf cooling sequence in the Globular Cluster Messier 4
TL;DR: The white dwarfs of the globular cluster M4 extend to approximately 2.5 mag fainter than the peak of the local Galactic disk white dwarf luminosity function as discussed by the authors.
Journal ArticleDOI
The Phantom divide in string gas cosmology
TL;DR: In this article, it was shown that non-perturbative string effects rule out this possibility, even if the NEC violation in question is only “effective”, which does not depend on assuming that the spatial sections remain precisely flat in the early Universe.
Gauge-Invariant Cosmological Perturbations
TL;DR: The physical interpretation of perturbations of homogeneous, isotropic cosmological models in the early Universe, when the perturbation is larger than the particle horizon, is clarified by defining a complete set of gauge-invariant variables as discussed by the authors.
Journal ArticleDOI
Creating statistically anisotropic and inhomogeneous perturbations
TL;DR: In this article, it is shown that if the universe contains an appropriate triad of scalar fields with spatially constant but non-zero gradients, it is possible to generate statistically anisotropic and inhomogeneous primordial perturbations, even though the energy?momentum tensor of the triad itself is invariant under translations and rotations.
Journal ArticleDOI
Creating Statistically Anisotropic and Inhomogeneous Perturbations
TL;DR: In this paper, the authors show that if the universe contains an appropriate triad of scalar fields with spatially constant but non-zero gradients, it is possible to generate statistically anisotropic and inhomogeneous primordial perturbations, even though the energy momentum tensor of the triad itself is invariant under translations and rotations.
References
More filters
Journal ArticleDOI
First year Wilkinson Microwave Anisotropy Probe (WMAP) observations: Preliminary maps and basic results
Charles L. Bennett,Mark Halpern,Gary Hinshaw,N. Jarosik,Alan J. Kogut,Michele Limon,Michele Limon,S. S. Meyer,Lyman A. Page,David N. Spergel,Gregory S. Tucker,Gregory S. Tucker,Gregory S. Tucker,Edward J. Wollack,Edward L. Wright,Cris W. Barnes,M. R. Greason,Robert S. Hill,Eiichiro Komatsu,M. R. Nolta,N. Odegard,Hiranya V. Peiris,Licia Verde,Janet Weiland +23 more
TL;DR: In this paper, the authors present full sky microwave maps in five frequency bands (23 to 94 GHz) from the WMAP first year sky survey, which are consistent with the 7 in. full-width at half-maximum (FWHM) Cosmic Background Explorer (COBE) maps.
Journal ArticleDOI
Type Ia supernova discoveries at z > 1 from the Hubble Space Telescope: Evidence for past deceleration and constraints on dark energy evolution
Adam G. Riess,Louis-Gregory Strolger,John L. Tonry,Stefano Casertano,Henry C. Ferguson,Bahram Mobasher,Peter Challis,Alexei V. Filippenko,Saurabh Jha,Weidong Li,Ryan Chornock,Robert P. Kirshner,Bruno Leibundgut,Mark Dickinson,Mario Livio,Mauro Giavalisco,Charles C. Steidel,Txitxo Benítez,Zlatan Tsvetanov +18 more
TL;DR: For a flat universe with a cosmological constant, the transition between the two epochs is constrained to be at z = 0.46 ± 0.13 as mentioned in this paper, and w = -1.02 ± (and w < -0.76 at the 95% confidence level) for an assumed static equation of state of dark energy.
Journal ArticleDOI
Type Ia Supernova Discoveries at z>1 From the Hubble Space Telescope: Evidence for Past Deceleration and Constraints on Dark Energy Evolution
Adam G. Riess,Louis-Gregory Strolger,John L. Tonry,Stefano Casertano,Henry C. Ferguson,Bahram Mobasher,Peter Challis,Alexei V. Filippenko,Saurabh Jha,Weidong Li,Ryan Chornock,Robert P. Kirshner,Bruno Leibundgut,Mark Dickinson,Mario Livio,Mauro Giavalisco,Charles C. Steidel,Narciso Benítez,Zlatan Tsvetanov +18 more
TL;DR: In this article, the first conclusive evidence for cosmic deceleration that preceded the current epoch of cosmic acceleration was provided by the discovery of 16 Type Ia supernovae with the Hubble Space Telescope (HST).
Journal ArticleDOI
Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant
Wendy L. Freedman,Barry F. Madore,Barry F. Madore,Brad K. Gibson,Laura Ferrarese,Daniel D. Kelson,Shoko Sakai,Jeremy Mould,Robert C. Kennicutt,Holland C. Ford,John A. Graham,John P. Huchra,Shaun M. G. Hughes,Garth D. Illingworth,Lucas M. Macri,Peter B. Stetson +15 more
TL;DR: In this paper, the final results of the Hubble Space Telescope (HST) Key Project to measure the Hubble constant are presented, and the results are based on a Cepheid calibration of several secondary distance methods applied over the range of about 60-400 Mpc.
Journal ArticleDOI
Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant
Wendy L. Freedman,Barry F. Madore,Barry F. Madore,Brad K. Gibson,Laura Ferrarese,Daniel D. Kelson,Shoko Sakai,Jeremy Mould,Robert C. Kennicutt,Holland C. Ford,John A. Graham,John P. Huchra,Shaun M. G. Hughes,Garth D. Illingworth,Lucas M. Macri,Peter B. Stetson +15 more
TL;DR: In this article, the final results of the Hubble Space Telescope Key Project to measure the Hubble constant are presented, and the implications of these results for cosmology are discussed and compared with other, global methods for measuring the Hubble constants.