Is negative kinetic energy meta-stable?

测量、误差和负动能

Measurements, errors, and negative kinetic energy

对测量误差的分析产生了对量子粒子渗透到经典禁区的新见解。除了“物理”值，现实的测量产生“非物理”值，我们表明，可以形成一个一致的模式。在一个经典的禁戒区域中分离出一个粒子的实验得到了它的动能的负值。这些值实现了在以前的作品中讨论的{ \it弱值}的概念。

Einstein-Maxwell Dirichlet walls, negative kinetic energies, and the adiabatic approximation for extreme black holes

The gravitational Dirichlet problem -- in which the induced metric is fixed on boundaries at finite distance from the bulk -- is related to simple notions of UV cutoffs in gauge/gravity duality and appears in discussions relating the low-energy behavior of gravity to fluid dynamics. We study the Einstein-Maxwell version of this problem, in which the induced Maxwell potential on the wall is also fixed. For flat walls in otherwise-asymptotically-flat spacetimes, we identify a moduli space of Majumdar-Papapetrou-like static solutions parametrized by the location of an extreme black hole relative …

关于负张力膜场论正则化的稳定性

On the stability of field-theoretical regularizations of negative tension branes

任何试图通过一个体标量来正则化一个负张力膜的尝试，都需要这个场是一个鬼场。在这方面，我们可以尝试以多种方式进行改进。例如，有人建议使用一个动力学项不是正负号确定的场，希望背景可以是总体稳定的。我们表明，这是不是这样的情况下，系统的物理扰动（包括重力）不延伸到整个零的动力学项，因此，所有的模式是完全本地化的动力学项是积极的，或它是负的，这第二种类型的模式是鬼。我们表明，这一结论并不依赖于具体的选择为动力学和潜在的功能，散装标量。

Phantom Dark Energy Models with Negative Kinetic Term

We examine phantom dark energy models derived from a scalar field with a negative kinetic term for which V(phi) approaches infinity asymptotically. All such models can be divided into three classes, corresponding to an equation of state parameter w with asymptotic behavior w -> -1, w -> w_0 < -1, and w -> infinity. We derive the conditions on the potential V(phi) which lead to each of these three types of behavior. For models with w -> -1, we derive the conditions on V(phi) which determine whether or not such models produce a future big rip. Observational constraints are derived on two classes…

Towards a Solution of the Negative Mode Problem in Quantum Tunnelling with Gravity

In the absence of gravity, one can prove that tunnelling instantons exhibit exactly one negative mode in their spectrum of fluctuations. It is precisely the existence of this tunnelling negative mode that warrants an interpretation of these solutions as mediating the decay of a metastable vacuum. In the presence of gravity the situation is much more subtle, not least because of diffeomorphism invariance. New complications arise here: in particular, the kinetic term of the fluctuations can change sign somewhere along the instanton. We show that in this case the mode functions remain non-singula…

具有正负指数势的宇宙学

Cosmology with positive and negative exponential potentials

我们提出了一个相平面分析宇宙学包含一个标量场$ϕ$与指数势$V \propto \exp(-λκϕ)$其中$κ^2 = 8πG$和$V$可以是积极的或消极的。我们发现，幂律动力学势标度解只存在足够平坦（$λ^2<6$）的正电位或陡峭（$λ^2>6$）的负电位。后者对应于一类具有负势的不断膨胀的宇宙学。然而，我们表明，这些扩展的解决方案与负的潜力是不稳定的存在下，普通物质，空间曲率或各向异性剪切，和一般的解决方案总是坍缩到一个奇点。幂律动力学势标度解是坍缩宇宙中陡负势（ekpyrotic场景）的晚期吸引子，并且对物质，曲率或剪切扰动稳定。否则，动力学主导的解决方案是在崩溃（前大爆炸的情况下）的吸引子，并仅在边缘稳定的各向异性剪切。