Results 101 to 110 of about 618 (129)

Analysis of s-t symmetric classical S-matrices

Journal of High Energy Physics
We analyze the complex analytic properties of classical i.e. tree-level S-matrices for four scalar particles with s-t crossing symmetry, involving an infinite number of exchanges.
Abhijit Gadde, Shraiyance Jain
doaj   +1 more source

braneworld cosmology and holography [PDF]

, 2002
This thesis is devoted to studying two important aspects of braneworld physics: their cosmology and their holography. We examine the Einstein equations induced on a general (n - 2)-brane of arbitrary tension, embedded in some n-dimensional bulk.
Padilla, Antonio
core  

One-loop phenomenology in brane models [PDF]

, 2005
Particular examples of one-loop string effects are explored in the context of brane-based realizations of the Standard Model. We firstly examine the consequences of a phenomenon known as Kinetic Mixing, which couples hidden U(1) gauge factors to visible ...
Schofield, Ben
core  

On unitarity of the hypergeometric amplitude

Journal of High Energy Physics
The hypergeometric amplitude is a one-parameter deformation of the Veneziano amplitude for four-point tachyon scattering in bosonic string theory that is consistent with S-matrix bootstrap constraints.
Gareth Mansfield, Marcus Spradlin
doaj   +1 more source

Positivity of the Veneziano amplitude in ten dimensions

Journal of High Energy Physics
The Veneziano amplitude describing the tree-level scattering of four open superstrings is expected to be consistent with unitarity in ten spacetime dimensions.
Gareth Mansfield
doaj   +1 more source

TWO-LOOP VACUUM ENERGY For Calabi-Yau Orbifold Models

, 2013
A precise evaluation of the two-loop vacuum energy is provided for certain Z2×Z2 Calabi-Yau orbifold models in the Heterotic string. The evaluation is based on the recent general prescription for superstring perturbation theory in terms of integra-tion ...
Eric D'Hoker, Duong H. Phong
core  

Attraction to a radiation-like era in early superstring cosmologies

, 2009
38 pages, 4 figuresStarting from an initial classical four dimensional flat background of the heterotic or type II superstrings, we are able to determine at the string one-loop level the quantum corrections to the effective potential due to the ...
Kounnas, Costas, Partouche, Herve, Bourliot, Francois   +2 more
core   +1 more source

Dilaton vertices of the closed superstring and the heterotic string

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 1988
Abstract BRST - and conformally invariant dilaton vertices of the closed superstring and the heterotic string are constructed, whose counter terms are consistent with the dilaton terms introduced in the non-linear sigma model approach of string theory.
Bang-Gui Liu
exaly   +2 more sources

Dilaton incoming vertices of the closed superstring and the heterotic string

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 1990
Abstract BRST- and conformally-invariant incoming vertices for the dilaton are constructed in the closed superstring and the heterotic string theories. The BRST-invariant (0, 0) conformal field corresponding to the dilaton is determined up to a BRST cohomology transformation.
Hikaru Sato
exaly   +2 more sources

Three-loop β-functions for the superstring and heterotic string

Nuclear Physics B, 1988
Abstract The β-function for the (1,1) superstring is calculated explicitly up to three loops, using two different choices of the fermion quantum field. In both cases the bosonic contribution is exactly cancelled by the fermionic contribution. The calculation is repeated for the heterotic string and the non-vanishing β-function is shown to be ...
D A Ross
exaly   +2 more sources