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N Kaloper

Publications and source records attributed to N Kaloper.

7 recordsLinked to original sources

Compact hyperbolic extra dimensions: branes, kaluza-klein modes, and cosmology

We reconsider theories with low gravitational (or string) scale M(*) where Newton's constant is generated via new large-volume spatial dimensions, while standard model states are localized to a 3-brane. Utilizing compact hyperbolic manifolds we show that the spectrum of Kaluza-Klein modes is radically altered. This allows the early Universe to evolve normally up to substantial temperatures, and completely negates the astrophysical constraints on M(*). Furthermore, an exponential hierarchy between the usual Planck scale and the true fundamental scale of physics can emerge with only O(1) coefficients. The linear size of the internal space remains small. The proposal has striking testable signatures.

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Infinitely large new dimensions

We construct intersecting brane configurations in anit-de Sitter (AdS) space which localize gravity to the intersection region, generalizing the trapping of gravity to any number n of infinite extra dimensions. Since the 4D Planck scale M(Pl) is determined by the fundamental Planck scale M(*) and the AdS radius L via the familiar relation M(2)(Pl) approximately M(2+n)(*)L(n), we get two kinds of theories with TeV scale quantum gravity and submillimeter deviations from Newton's law. With M(*) approximately TeV and L approximately submillimeter, we recover the phenomenology of theories with large extra dimensions. Alternatively, if M(*) approximately L-1 approximately M(Pl), and our 3-brane is at a distance of approximately 100M(-1)(Pl) from the intersection, we obtain a theory with an exponential determination of the weak/Planck hierarchy.

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