The materials approach to quantum spacetime

量子时空的材料方法

• 批准号: MR/X034453/1
• 负责人: Tarek Anous
• 金额: $ 193.55万
• 依托单位: Queen Mary University of London
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FX034453%2F1
• 关键词: materials; approach; quantum; spacetime

The effects of gravity are known to all of us: responsible both for falling apples and planetary orbits, but it remains the least well-understood force in nature. An open question in our conceptualization of gravity regards whether information is destroyed in gravitational processes.Black holes, formed from the collapse of stars, are a beautiful testing ground for these ideas. Consider a diary, containing deeply personal secrets that must be kept from public view at all costs. Is it possible to destroy the information contained within by throwing the diary into a black hole? While this might seem useful in practice, the implications for fundamental physics would be disastrous. A self-consistent physical theory should not allow for information destruction, as this would imply a basic inability to predict the outcomes of experiments; negating the entire paradigm of the scientific method and the validity of hypothesis testing. Cue Hawking's information paradox, which definitively shows that, within the framework of Einstein's general relativity, black holes do indeed destroy information. This suggests that we must search for a theory that can replace Einstein's general relativity, while nevertheless reproducing all of its successful predictions in the realm of astronomy and cosmology. This is a daunting but necessary task.Black holes are not the only realm where Einstein's equations reveal inconsistencies: astronomical surveys suggest that our universe is expanding, and similarly to black holes, an expanding universe potentially destroys the information in the diary, if left alone for eons. If we are to understand the origins of our expanding universe, it is imperative that we build theoretical models that accurately describe expanding space without the problematic information loss.To get at the crux of the information paradox, I am looking at frameworks that could eventually replace general relativity. My approach is to treat the fabric of space as a `material' to be experimented on. Of course, being a theoretical physicist means that my experiments will be `thought-' or `gedanken-' experiments, but nonetheless Einstein's equations reveal that under certain conditions, or in the presence of certain types of matter, spacetime exhibits phase transitions, much like how water turns to gas if the temperature and pressure are tuned beyond specific values. My goal is to use such thought experiments to guide a search for new microscopic theories that will provide a better understanding of the fabric of the universe and its cosmic origins. These new theories will still describe the known features of gravity, but without the problematic information loss, and simultaneously have the potential to reveal new undiscovered properties of spacetime and our universe.

重力的影响是我们所有人都知道的：它既导致苹果下落，也导致行星轨道，但它仍然是自然界中最不为人所知的力。我们对引力概念的一个悬而未决的问题是信息是否会在引力过程中被破坏。由恒星坍塌形成的黑洞是这些想法的一个美丽的试验场。考虑一本日记，其中包含必须不惜一切代价不让公众看到的深刻的个人秘密。是否可以通过将日记扔进黑洞来销毁其中包含的信息？虽然这在实践中似乎很有用，但对基础物理学的影响将是灾难性的。自洽的物理理论不应允许信息破坏，因为这意味着基本无法预测实验结果；否定科学方法的整个范式和假设检验的有效性。提示霍金的信息悖论，它明确地表明，在爱因斯坦广义相对论的框架内，黑洞确实会破坏信息。这表明我们必须寻找一种可以取代爱因斯坦广义相对论的理论，同时重现其在天文学和宇宙学领域的所有成功预测。这是一项艰巨但必要的任务。黑洞并不是爱因斯坦方程揭示不一致的唯一领域：天文调查表明我们的宇宙正在膨胀，与黑洞类似，膨胀的宇宙如果不去管它可能会破坏日记中的信息亿万年。如果我们要了解不断膨胀的宇宙的起源，我们就必须建立能够准确描述不断膨胀的空间而不会出现信息丢失问题的理论模型。为了找到信息悖论的症结所在，我正在寻找最终可以取代的框架广义相对论。我的方法是将空间结构视为要进行实验的“材料”。当然，作为一名理论物理学家意味着我的实验将是“思想”或“gedanken”实验，但尽管如此，爱因斯坦的方程表明，在某些条件下，或在某些类型的物质存在下，时空会表现出相变，很多就像如果温度和压力超出特定值，水就会变成气体。我的目标是利用此类思想实验来指导对新微观理论的探索，从而更好地理解宇宙的结构及其宇宙起源。这些新理论仍将描述已知的引力特征，但不会出现信息丢失的问题，同时有可能揭示时空和宇宙新的未被发现的特性。