Searcharxiv⌕ Search
Home/Archive/arXiv

arXiv · 0704.2198

Braneworld Cosmology

James M. Cline
View original source ↗Read source document ↗Export metadata ↓

Abstract

A brief review of the field of braneworld cosmology, from its inception with the large extra dimension scenario, to aspects of cosmology in warped extra dimensions, including the RS-I and RS-II models, braneworld inflation, the Goldberger-Wise mechanism, mirage cosmology, the radion-induced phase transition in RS-I, possible gravity wave signals, and the DGP model.

Explore related subjects

hep-thastro-phhep-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

James M. Cline. 2007-04-17. Braneworld Cosmology. https://arxiv.org/abs/0704.2198

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Kerr/CFT Traversable Wormhole with Fermionic Double-Trace Deformation

The construction of a traversable wormhole with double-trace deformation has been achieved so far by using boson fields as the perturbation. In this work, we study double-trace deformation with fermion fields in the two-sided Kerr background to open a traversable wormhole. We construct the fermionic double-trace deformation within the Kerr/CFT framework. We consider the near-horizon, near-extremal Kerr geometry, which is dual to a conformal field theory. The lack of fermionic superradiance let us describe the wormhole at every region, even at the off-axis region where bosonic field experiences instability due to superradiance. By choosing a certain coupling between the left and right boundaries, the two-point function is modified, and its first order correction contributes the negative energy to open the wormhole. The wormhole is most traversable when the perturbation is turned on at early times, with opening that depends on the mode's frequency, the black hole temperature, and the fermion mass. At late times, the average null energy has damped oscillation behavior until eventually reaches zero. Wormhole with lower temperature have less traversability and it is completely closed at extreme limit. The same traversability can also be reproduced by using eikonal method. On the other hand, rotation and the number of fields involved in the deformation can increases the upper bound on information transfer up to the order of the entropy. Additionally, symmetrical effective potential bumps connected by the wormhole can produce observable echoes. We find that the echo time delay cannot exceed the scrambling time of the black hole.

hep-th↗
arXiv2026

A Dispersive Bootstrap for the Virasoro-Shapiro Amplitude

We study the closed-string tree-level Virasoro-Shapiro amplitude using the dispersive S-matrix bootstrap. For the ten-dimensional maximally supersymmetric four-point amplitude, we impose analyticity, crossing symmetry, partial-wave unitarity, and Regge boundedness. With the massless graviton pole kept explicitly, the resulting dispersion relations and crossing null constraints give numerical bounds on the leading low-energy coefficients normalized by the gravitational coupling, which agree at our reference truncation with earlier bounds from smeared functionals. We then introduce a Virasoro-inspired ansatz, which becomes a set of nonlinear relations among Wilson coefficients and shrinks the allowed region toward the Virasoro-Shapiro trajectory. Finally, we study a gravity-pole-subtracted setup, where the regular part of the amplitude has a well-defined forward limit. In this stripped problem, on the slice of the leading coefficient that places the first Virasoro-Shapiro resonance at the cutoff, the nonlinear constraints reduce the allowed region to a small island containing the Virasoro-Shapiro point. Imposing the ansatz to all orders, together with spectral assumptions not used in the numerics, we show analytically that positivity selects the Virasoro-Shapiro spectrum.

hep-th↗
arXiv2026

Combinatorial aspects of holographic quantum secret sharing

We introduce combinatorial holographic quantum secret sharing (CHQSS) for a bulk subregion in AdS$_3$/CFT$_2$ to study how logical information of the bulk subregion is encoded in the boundary and protected from erasures of boundary subregions. We introduce a distance, a reconstruction threshold, and a secret threshold to characterize CHQSS schemes. We present the phase transitions of multipartite entanglement wedges in a symmetric setup and observe multiple distinct phase transition points. The distance and thresholds depend on the holographic phase and the choice of bulk subregion. We derive the maximum distance. Moreover, we derive the relations between the distance and the thresholds. We construct a family of CHQSS schemes in the symmetric setting that includes perfect threshold CHQSS and perfect non-threshold CHQSS.

hep-th↗