Thermodynamic aspects of quantum gravity

量子引力的热力学方面

• 批准号: RGPIN-2017-05024
• 负责人: Smolin, Lee
• 金额: $ 3.88万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=690414
• 关键词: Thermodynamic; aspects; quantum; gravity

Quantum gravity is the search for the completion of the revolution in science that Einstein launched in 1905 with his simultaneous proposal of quantum theory and relativity theory. In this proposal I put forward a new strategy for completing Einstein's revolution, based on discovering new principles for quantum gravity. The aim of this proposal is to make significant progress on the problem of quantum gravity by building on a persistent theme of research the last 45 years, which is the thermodynamic nature of gravitation. ******There is ample evidence that the dynamics of general relativity, as expressed by the Einstein equations, embody phenomena that have a close analogue to thermodynamics. Such evidence comes from the classical laws of black hole mechanics, which apply to stationary black hole solutions. These suggest an identification of horizon area with entropy and surface gravity with temperature. When we take the mass of the black hole to correspond to energy, these quantities satisfy relations that have the form of the laws of thermodynamics. ******Over the last two decades, a very exciting hypothesis has been developed, according to which classical spacetime is an emergent phenomenon, arising from a fundamental quantum description, given by a discrete theory of fundamental processes. Hence, causation, energy and momentum are fundamental. Moreover, the Einstein equations of general relativity arise as the expression of the laws of thermodynamics applied to the fundamental quantum processes. ******In recent years the PI and others have developed this hypothesis, taking for the fundamental processes a model of quantum spacetime called spin foam models. There have also been inspiring insights obtained by combining entanglement entropy with holography. The present proposal builds on this recent progress in four ways.******First, we seek to discover the principles which underlie the fundamental quantum processes. These include a version of the holographic principle as well as an extension of the equivalence principle to histories of quantum processes. ******Second, we will derive general relativity directly as a consequence of the principles, combined with the laws of thermodynamics.******Third, we seek to develop new experimental predictions directly from these principles, giving us new quantum gravity phenomena by which the principles may be tested.******Fourth, we will test whether specific models of quantum spacetime satisfy the principles. These include spin foam models, proposals for background independent string theories, causal set models and dynamical triangulation models.******We believe this is a strategy to discover quantum gravity which takes best advantage of the deep links connecting gravity to thermodynamics as well as recent insights regarding holography and entanglement. It also builds on progress in various models of quantum spacetime.

量子引力是对爱因斯坦在1905年发起的科学革命的探索，他同时提出了量子理论和相对论。在这个提议中，我提出了一个完成爱因斯坦革命的新战略，这个战略是基于发现量子引力的新原理。这一提议的目的是通过在过去45年来研究的一个持久主题--引力的热力学本质--的基础上，在量子引力问题上取得重大进展。*有充分的证据表明，爱因斯坦方程所表达的广义相对论动力学包含了与热力学有密切相似的现象。这些证据来自黑洞力学的经典定律，这些定律适用于静止的黑洞解。这就提出了用熵来识别视界区域，用温度来识别表面重力的方法。当我们把黑洞的质量对应于能量时，这些量满足热力学定律形式的关系。在过去的二十年里，一个非常令人兴奋的假说被提出，根据这个假说，经典时空是一种新出现的现象，起源于由基本过程的离散理论给出的基本量子描述。因此，因果关系、能量和动量是根本。此外，广义相对论的爱因斯坦方程是热力学定律应用于基本量子过程的表达式。*近年来，PI和其他人发展了这一假说，将称为自旋泡沫模型的量子时空模型作为基本过程。通过将纠缠熵与全息术相结合，也获得了一些鼓舞人心的见解。目前的提议在四个方面建立在这一最新进展的基础上。*首先，我们寻求发现构成基本量子过程的原理。其中包括全息原理的一个版本，以及等价性原理对量子过程历史的扩展。*第二，我们将根据这些原理直接推导出广义相对论，并结合热力学定律。*第三，我们寻求直接从这些原理发展新的实验预测，给我们新的量子引力现象，可以用来检验这些原理。*第四，我们将测试特定的量子时空模型是否满足这些原理。这些模型包括自旋泡沫模型、背景独立弦理论、因果集合模型和动力学三角模型。*我们认为这是一种发现量子引力的策略，它最大限度地利用了引力与热力学之间的深层联系，以及关于全息照相和纠缠的最新见解。它还建立在各种量子时空模型的进展基础上。