We demonstrate the possibility of examining cosmological signatures in the DBI inflation setup using the BGMPZ solution, a one-parameter family of geometries for the warped throat which interpolate between the Maldacena-Nunez and Klebanov-Strassler solutions. The warp factor is determined numerically and subsequently used to calculate cosmological observables including the scalar and tensor spectral indices, for a sample point in the parameter space. As one moves away from the KS solution for the throat the warp factor is qualitatively different, which leads to a significant change for the observables, but also generically increases the non-Gaussianity of the models. We argue that the different models can potentially be differentiated by current and future experiments.
本文提出了一个在弯曲喉道中相对论D-膜暴胀的温暴胀模型，它具有Dirac Born Infeld（DBI）动力学项，并通过耗散项与辐射耦合。扰动冻结在声地平线和功率谱的耗散参数和声速参数的组合确定。热耗散改善了{ \it eta}问题，软化了来自额外维度体积和来自张量标量比的观测界限的理论约束。暖DBI模型可以导致明显的等边型非高斯性。作为一个唯象模型，忽略紧化约束，我们表明，大场的温暖的通货膨胀模型不一定会产生一个大的张量标量比。
Combined local and equilateral non-Gaussianities from multifield DBI inflation
我们研究了Dirac Born Infeld（DBI）暴胀的多场性质。更具体地说，我们考虑一个膨胀阶段驱动的径向运动的D-膜在一个圆锥形的喉咙，并确定如何D-膜波动的角度方向可以转换成曲率扰动时，快子不稳定性出现在膨胀结束。同时存在的多个领域和非标准的动力学项给出了本地和等边形状的非高斯双谱。我们还研究了三谱，指出它获得了一个特殊的动量依赖分量，其振幅由$f_{NL}^{loc} f_{NL}^{eq}$给出。我们表明，这种关系是有效的，在每一个多场DBI模型，特别是对于任何膜轨迹，从而构成了一个有趣的观测签名，这种情况下。
Multi-centered bubbling solutions are black hole microstate geometries that arise as smooth solutions of 5-dimensional $\mathcal{N}=2$ Supergravity. When these solutions reach the scaling limit, their resulting geometries develop an infinitely deep throat and look arbitrarily close to a black hole geometry. We depict a connection between the scaling limit in the moduli space of Microstate Geometries and the Swampland Distance Conjecture. The naive extension of the Distance Conjecture implies that the distance in moduli space between a reference point and a point approaching the scaling limit i…
We consider the fate of a massless (or ultra-relativistic massive) string probe propagating down the BTZ-like throat of a microstate geometry in the D1-D5 system. Far down the throat, the probe encounters large tidal forces that stretch and excite the string. The excitations are limited by the very short transit time through the region of large tidal force, leading to a controlled approximation to tidal stretching. We show that the amount of stretching is proportional to the incident energy, and that it robs the probe of the kinetic energy it would need to travel back up the throat. As a conse…
Backreacted DBI Magnetotransport with Momentum Dissipation
我们研究磁输运的全息Dirac Born Infeld模型，考虑到几何上的反向反应的影响。我们考虑的理论包括轴子标量，引入打破平移对称性和产生动量耗散。这些理论的直流电导率矩阵的一般结构是非常丰富的，是显着更复杂的比在探针近似。我们发现新的类的黑膜解决方案，包括几何表现出Lifshitz标度和超标度违反，并检查其对系统的传输特性的影响。根据理论参数的选择，这些背景可以导致金属或绝缘行为。在一系列的动力学解决方案中观察到负磁阻。一些新的反反应几何形状也支持磁场诱导的金属-绝缘体转变。
We compute the quasi-normal frequencies of scalars in asymptotically-flat microstate geometries that have the same charge as a D1-D5-P black hole, but whose long BTZ-like throat ends in a smooth cap. In general the wave equation is not separable, but we find a class of geometries in which the non-separable term is negligible and we can compute the quasi-normal frequencies using WKB methods. We argue that our results are a universal property of all microstate geometries with deeply-capped BTZ throats. These throats generate large redshifts, which lead to exceptionally-low-energy states with ext…
We study the brane/flux annihilation in the double-throat system in which the corresponding cycles of two throats are homologically equivalent. When we put $\overline{\rm D3}$-branes at only one of throat tips, two throats are no longer identical. Then the brane/flux annihilation can be interpreted as the process for reducing the difference between two throat geometries through the transition to the supersymmetric vacuum. To see this, we describe the changes in the amounts of the NSNS 3-form flux supporting the B-cycle contained in two throat regions during the brane/flux annihilation. We also…
Within the Russo-Susskind-Thorlacius (RST) two-dimensional model that includes a scalar (dilaton) field we address the important question of how the classical black hole geometry is modified in a semiclassical gravitational theory. It is the principle goal of this paper to analyze what is the back-reacted geometry that corresponds to a given quantum state. The story is shown to be dramatically different for the Hartle-Hawking state (HH) and for the Boulware state. In the HH case the back-reacted geometry is a modification of the classical black hole metric that still has a smooth horizon with …
Berry Picking: Random Wave Chaos Hierarchy for BPS Microstate Geometries
Center for the Study of Complex Systems, Institute of Physics Belgrade, University of Belgrade（贝尔格莱德大学物理研究所复杂系统研究中心）；Faculty of Physics, University of Belgrade（贝尔格莱德大学物理学院）
We examine transport in a holographic model in which the dynamics of the charged degrees of freedom is described by the nonlinear Dirac-Born-Infeld (DBI) action. Axionic scalar fields are included to break translational invariance and generate momentum dissipation in the system. Scaling exponents are introduced by using geometries which are nonrelativistic and hyperscaling-violating in the infrared. In the probe DBI limit the theory reproduces the anomalous temperature dependence of the resistivity and Hall angle of the cuprate strange metals, $ρ\sim T$ and $\cotΘ_H \sim T^2$. These scaling la…
A fundamental ingredient in wormhole physics is the flaring-out condition at the throat which, in classical general relativity, entails the violation of the null energy condition. In this work, we present the most general conditions in the context of modified gravity, in which the matter threading the wormhole throat satisfies all of the energy conditions, and it is the higher order curvature terms, which may be interpreted as a gravitational fluid, that support these nonstandard wormhole geometries. Thus, we explicitly show that wormhole geometries can be theoretically constructed without the…
In this paper we study non-perturbative instabilities in Anti de-Sitter vacua arising from flux compactifications of string models with broken supersymmetry. In the semi-classical limit, these processes drive the vacua towards lower fluxes, which translate into higher curvatures and higher string couplings. In order to shed some light on this regime, we provide evidence for a description in terms of branes, which generate near-horizon AdS throats. To this end, we study the attractor properties of the geometries near the throat, and we also characterize their asymptotics away from it. We also d…
We present the construction of several microstate geometries of the supersymmetric D1-D5-P black hole in which, within six-dimensional supergravity, the momentum charge is carried by a vector field. The fully backreacted geometries are smooth and horizonless: They are asymptotically AdS$_3 \times S^3$ with an AdS$_2$ throat that smoothly caps off. We propose a holographic dual for these bulk solutions and discuss their extension to asymptotically flat space. In addition, we present several uplifts of the full six-dimensional supersymmetric ansatz to ten-dimensions. In particular, we show that …
我们系统地构造了与1+1维（0，4）共形场论对偶的几何，这些场论产生于M-理论的S^1 x CY_3紧化中包裹的M5-膜的低能描述.这包括了大量多中心黑洞的束缚态渐近到AdS_3 × S^2。此外，我们发现许多几何形状，开发多个，相互去耦AdS_3 x S^2喉。我们认为，有一个有用的一对一的对应关系的空间的解决方案和特定的限制IIA型吸引流树的连接组件。我们指出，小的超对称BTZ黑洞在S^2上存在一个定域的热力学不稳定性，它是著名的AdS-Schwarzschild定域不稳定性的一个超对称的、精确可解的类似物，并将其与四维的“熵之谜”联系起来。我们讨论了这表明的相变，并开始这些结果的CFT解释。
