美国物理学家称找到观察六维空间的方法.pdfVIP

P H Y S I C A L R E V I E W L E T T E R S week ending PRL 98, 051301 (2007) 2 FEBRUARY 2007 Observing the Geometry of Warped Compactification via Cosmic Inflation Gary Shiu and Bret Underwood Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, USA (Received 20 October 2006; published 2 February 2007) Using Dirac-Born-Infeld inflation as an example, we demonstrate that the detailed geometry of warped compactification can leave an imprint on the cosmic microwave background. We compute cosmic microwave background observables for Dirac-Born-Infeld inflation in a generic class of warped throats and find that the results (such as the sign of the tilt of the scalar perturbations and its running) depend sensitively on the precise shape of the warp factor. In particular, we analyze the warped deformed conifold and find that the results can differ from those of other warped geometries, even when these geometries approximate well the exact metric of the warped deformed conifold. DOI: 10.1103/PhysRevLett.98.051301 PACS numbers: 98.80.Cq, 11.25.Wx It has long been recognized that observational cosmol- taining inflation by flattening the inflaton potential [6] or ogy provides a powerful window for testing fundamental limiting the speed of the branes [7], significant warping physics, especially theories whose energy scales are far is essential in reheating the Universe [ 14]. Far from the tip from what current accelerator e