Physics of computation and light sheet concept in the measurement of (4+n)-dimensional spacetime geometry

We analyze the limits that quantum mechanics imposes on the accuracy to which $(4+n)$-dimensional spacetime geometry can be measured. Using physics of computation and light sheet concept we derive explicit expressions for quantum fluctuations and explore their cumulative effects for various spacetime foam models.Comment: 5 page

Fermions on the brane in 6D with nonsingular exponential scale factors

We introduce new realistic brane-solutions with exponential scale factors in the 6D-space-time. We show that for these solutions the zero modes of all bulk fields are sharply localized at different positions on the brane and have "Gaussian shape" wave-functions in the extra space. We also explicitly show that in the model there are cases when exactly three fermion generations naturally arise only through gravity. Because of localized fermion modes are also stuck at different positions in the extra space, there is possibility to provide a framework for natural explaining the fermion mass hierarchy in terms of higher dimensional geography.Comment: 6 pages, revtex4,new section added, explicit forms of wavefunctions and of source functions added,corrected typo

Gravitational Localization of Matters in 6D

We present a new 3-brane solution to Einstein's equations in (1+5)-spacetime with a negative bulk cosmological constant. This solution is a stringlike defect solution with decreasing scale function approaching a finite non-zero value in the radial infinity. It is shown that all local fields are localized on the brane only through the gravitational interaction.Comment: 7 pages; added reference

About quantum fluctuations and holographic principle in (4+n)-dimensional spacetime

In the article we present explicit expressions for quantum fluctuations of spacetime in the case of $(4+n)$-dimensional spacetimes, and consider their holographic properties and some implications for clocks, black holes and computation. We also consider quantum fluctuations and their holographic properties in ADD model and estimate the typical size and mass of the clock to be used in precise measurements of spacetime fluctuations. Numerical estimations of phase incoherence of light from extra-galactic sources in ADD model are also presented.Comment: 5 page

Finsler Branes and Quantum Gravity Phenomenology with Lorentz Symmetry Violations

A consistent theory of quantum gravity (QG) at Planck scale almost sure contains manifestations of Lorentz local symmetry violations (LV) which may be detected at observable scales. This can be effectively described and classified by models with nonlinear dispersions and related Finsler metrics and fundamental geometric objects (nonlinear and linear connections) depending on velocity/ momentum variables. We prove that the trapping brane mechanism provides an accurate description of gravitational and matter field phenomena with LV over a wide range of distance scales and recovering in a systematic way the general relativity (GR) and local Lorentz symmetries. In contrast to the models with extra spacetime dimensions, the Einstein-Finsler type gravity theories are positively with nontrivial nonlinear connection structure, nonholonomic constraints and torsion induced by generic off-diagonal coefficients of metrics, and determined by fundamental QG and/or LV effects.Comment: latex2e, 11pt, 34 pages, the version accepted to Class. Quant. Gra

Matter-gravity interaction in a multiply warped braneworld,

The role of a bulk graviton in predicting the signature of extra dimensions through collider-based experiments is explored in the context of a multiply warped spacetime. In particular it is shown that in a doubly warped braneworld model, the presence of the sixth dimension, results in enhanced concentration of graviton Kaluza Klein (KK) modes compared to that obtained in the usual 5-dimensional Randall-Sundrum model. Also, the couplings of these massive graviton KK modes with the matter fields on the visible brane turn out to be appreciably larger than that in the corresponding 5- dimensional model. The significance of these results are discussed in the context of KK graviton search at the Large Hadron Collider (LHC).Comment: 13 pages, 2 table