引力的热力学起源

Notes on microstates, Tsallis statistics and entropic gravity formalism

It is an old idea to realize Einstein's equations as a thermodynamical equation of state. Since then, there has been new conjectures to understand gravity from another point of view. In this way we can accept that the gravitational field is not an underlying one like an emergent force from other approaches based on the knowledge of relativity, quantum and black holes thermodynamics, and different statistical formalisms. One important question concerning this gravity/thermostatistics correspondence is whether the holographic screen could be well defined for a nonrelativistic case of a source ma…

广义引力理论与爱因斯坦引力理论在黑洞热力学上的等价性

Equivalence of black hole thermodynamics between a generalized theory of gravity and the Einstein theory

我们在广义引力理论中分析了黑洞的热力学，其拉格朗日量是度规、Ricci张量和标量场的任意函数。我们可以通过勒让德变换或保角变换将理论转换到爱因斯坦坐标系中。我们按照满足热力学热力学第一定律的Iyer-Wald定义，计算了原坐标系和Einstein坐标系下的热力学变量。我们证明了，如果两个坐标系中的时空都是渐近平坦的、正则的，并且具有非零温度的事件视界，那么在原坐标系中定义的所有物理变量都与在爱因斯坦坐标系中定义的物理变量相同.这一结果对于研究广义引力理论中第二定律是否仍然成立可能是有用的。

二维介子引力中U（1）荷的宇宙学常数

Cosmological constant as confining U(1) charge in two-dimensional dilaton gravity

本文将宇宙学常数作为一个物理参数，在二维量子引力的框架下处理。我们发现，宇宙学常数表现为一个U（1）荷与一个限制势，这种势需要一个新的Born-Infeld边界项的作用.自由能和其他感兴趣的化学量是从第一原理推导出来的，其方式基本上是与模型无关的。我们发现比热总存在肖特基反常，并解释了其物理原因。最后，我们将这些结果应用于具体的例子，如Anti-de Sitter-Schwarzschild-Tangherlini黑洞，Banados-Teitelboim-Zanelli黑洞和Jackiw-Teitelboim模型。

Einstein-Born-Infeld-Massive Gravity: adS-Black Hole Solutions and their Thermodynamical properties

In this paper, we study massive gravity in the presence of Born-Infeld nonlinear electrodynamics. First, we obtain metric function related to this gravity and investigate the geometry of the solutions and find that there is an essential singularity at the origin ($r=0$). It will be shown that due to contribution of the massive part, the number, types and places of horizons may be changed. Next, we calculate the conserved and thermodynamic quantities and check the validation of the first law of thermodynamics. We also investigate thermal stability of these black holes in context of canonical en…

Thermodynamical Structure of AdS Black Holes in Massive Gravity with Stringy Gauge-Gravity Corrections

Motivated by gauge/gravity group in the low energy effective theory of the heterotic string theory and novel aspects of massive gravity in the context of lattice physics, the minimal coupling of Gauss-Bonnet-massive gravity with Born-Infeld electrodynamics is considered. At first, the metric function is calculated and then the geometrical properties of the solutions are investigated. It is found that there is an essential singularity at the origin and the intrinsic curvature is regular elsewhere. In addition, the effects of massive parameters are studied and black hole solutions with multi hor…

Susceptibilities from holographic transport with topological term

In this note we calculate susceptibilities, as derivatives of a thermodynamical potential, for the general perturbative holographic set-up for transport with magnetic field, charge density and topological term, and compare with the quantities obtained in the standard $AdS_4$ dyonic black hole analysis of Hartnoll and Kovtun. We find that the results do not match, despite previous expectations.

A note on coarse graining and group representations

A coarse graining operation of spatially homogeneous quantum states based on an SU(1,1) Lie group structure has recently been proposed in [1] and used in [2] to compute an explicit renormalisation group flow in the context of loop quantum cosmology. In this note, we explain the group theoretical origin of this procedure and generalise previous results based on these insights. We also highlight how the group theoretical origin of these techniques implies their immediate generalisation to other Lie groups.

极小曲面的“热力学”与引力的熵源

`Thermodynamics' of Minimal Surfaces and Entropic Origin of Gravity

研究了静态时空中位于常时间片上的极小曲面的形变问题。本文给出了一个精确的、普适的极小曲面面积随附近点状粒子移动而变化的公式，它允许我们在极小曲面上引入局部温度，并假定普朗克单位的熵等于极小曲面面积的四分之一，从而用数学形式表示极小曲面面积的变化。这些结果有力地支持了最近的一个假设，即引力具有熵的起源，最小表面是一种全息屏幕。引力熵也获得了与屏幕上基本自由度的量子纠缠相关的明确的物理意义。

Phase transition of charged Black Holes in Brans-Dicke theory through geometrical thermodynamics

In this paper, we take into account black hole solutions of Brans-Dicke-Maxwell theory and investigate their stability and phase transition points. We apply the concept of geometry in thermodynamics to obtain phase transition points and compare its results with those, calculated in canonical ensemble through heat capacity. We show that these black holes enjoy second order phase transitions. We also show that there is a lower bound for the horizon radius of physical charged black holes in Brans-Dicke theory which is originated from restrictions of positivity of temperature. In addition, we find…

关于DFT强约束的CFT原点的注记

A Note on the CFT Origin of the Strong Constraint of DFT

在双场论中，受场论一致性的启发，将能级匹配条件推广为强约束条件。本文研究了这种约束的二维共形场论起源。最初处理的左，右移动作为独立的，我们计算环面配分函数以及广义Virasoro-Shapiro振幅。在非紧方向的强约束产生的Virasoro-Shapiro振幅的因式分解的物理状态所确定的模块不变的配分函数。根据同样的论证，沿着内部环形方向，没有类似的约束出现。

Notes on the Origin of Gravity and the Laws of Newton

Following Verlinde's recent work on the origin of gravity and the laws of Newton, we consider further the origin of the starting point of Verlinde's work and Unruh effect. Simple derivations are given for this starting point and Unruh effect with the standard theory about quantum mechanics, special relativity and 'vacuum' background based on the gauge field theory. Our studies give the physical origin of the Planck length. The present work supports further the idea that gravity is not a fundamental force. In the present work, the concept of holographic screen is not absolutely necessary to der…

Lecture notes on thermodynamics of ideal string gases and its application in cosmology

In these lecture notes I give a pedagogical introduction to the thermodynamics of ideal string gases. The computation of thermodynamic quantities in the canonical ensemble formalism will be shown in detail with explicit examples. Attention will be given mainly to the thermodynamical consequences of string degrees of freedom, where I will especially address i) the Hagedorn temperature, a critical temperature above which the canonical ensemble description breaks down, which can be the onset point of some instability of the string gas; ii) the phase structure arising from compactification, embodi…

关于膜生成的一个注记

A note on brane creation

讨论了膜生成过程的M理论起源。

关于广义量子电动力学中辐射诱导Lorentz和CPT违反Chern-Simons类项的注记

A Note on the Radiatively Induced Lorentz and CPT Violated Chern-Simons-like Term in the Extended Quantum Electrodynamics

我们证明了在扩展QED中由量子修正引起的类Chern-Simons项的不确定性应该与精确的费米传播子的近似无关，这与文献[1]中的观点相矛盾。[19]第10段。进一步，我们利用原始的t Hooft-Veltman维数正则化研究了诱导的类Chern-Simons项，并再现了由规范对称性分析得到的结果.这一事实表明，模糊性的根源应该在于不同的正则化方案的选择。

热力学中隐藏的对称性和相对论的出现

Hidden symmetries for thermodynamics and emergence of relativity

Erik Verlinde最近提出了一个关于引力的热力学起源的想法。虽然这是一个美丽的想法，可以解决引力理论中许多长期存在的问题，但它也引发了许多其他问题。在这篇文章中，我将评论Verlinde的建议，特别强调相对性原理的物理起源的一些问题。我们发现，存在着一个包含时空的庞加莱群的热力学隐对称性的大群，在庞加莱群中空间是突现的。这就解释了相对性原理的热力学起源。