Braneworlds, graviton production, dynamical Casimir effect

Graviton production in anti-de Sitter braneworld cosmology: A fully consistent treatment of the boundary condition

In recent work by two of us, [Durrer & Ruser, PRL 99, 071601 (2007); Ruser & Durrer PRD 76, 104014 (2007)], graviton production due to a moving spacetime boundary (braneworld) in a five dimensional bulk has been considered. In the same way as the presence of a conducting plate modifies the electromagnetic vacuum, the presence of a brane modifies the graviton vacuum. As the brane moves, the time dependence of the vacuum leads to particle creation via the so called 'dynamical Casimir effect'. In our previous work a term in the boundary condition which is linear in the brane velocity has been neg…

Spontaneous localization on a brane via a gravitational mechanism

In this letter we introduce a novel way to spontaneously localize particles (including gauge bosons) and gravitons kinetic terms on a four-dimensional brane via a gravitational mechanism. The model underlying this localization mechanism can be considered as a high-energy resolution of the so-called braneworlds scenario. In particular, we show how to construct a braneworld with induced gravity without pathologies. Finally, we argue that the brane is only stable if its own mass does not exceed a critical value related to the particles-gravity couplings.

Brane Stabilization and Regionality of Extra Dimensions

Extra dimensions are a common feature of beyond the Standard Model physics. In a braneworld scenario, local physics on the brane can depend strongly on the brane's location within the bulk. Generically, the relevant properties of the bulk manifold for the physics on/of the brane are neither local nor global, but depend on the structure of finite regions of the bulk, even for locally homogeneous and isotropic bulk geometries. In a recent work, various mechanisms (in a braneworld context) were considered to stabilize the location of a brane within bulk spaces of non-trivial topology. In this wor…

视界之外的额外维度

Extra Dimensions Beyond the Horizon

本研究提出一种第五维度紧致化的双曲翘曲膜世界模型，通过额外维度的两个标度解释四维普朗克质量与宇宙学常数的层级，预言了可探测的有质量自旋2引力子，并讨论了模型的宇宙学应用障碍。

Brane Localization and Stabilization via Regional Physics

Extra-dimensional scenarios have become widespread among particle and gravitational theories of physics to address several outstanding problems, including cosmic acceleration, the weak hierarchy problem, and the quantization of gravity. In general, the topology and geometry of the full spacetime manifold will be non-trivial, even if our ordinary dimensions have the topology of their covering space. Most compact manifolds are inhomogeneous, even if they admit a homogeneous geometry, and it will be physically relevant where in the extra-dimensions one is located. In this letter, we explore the u…

四维有效嵌套翘曲几何中的模动力学及若干宇宙学启示

Moduli Dynamics in Effective Nested Warped Geometry in Four Dimensions and Some Cosmological Implications

本文研究嵌套翘曲膜世界中模场的四维有效动力学，发现dS膜上第一个模方向存在亚稳态极小值，并论证沿该方向的慢滚暴胀最可行，而沿更高模方向的慢滚因需要非物理的半径层级而不受观测支持。