NRST · Foundation of Nonrelativistic String Theory and Its Applications to Holography

Foundation of Nonrelativistic String Theory and Its Applications to Holography

The quest for quantum gravity that unifies general relativity and quantum mechanics poses one of the most profound puzzles in modern theoretical physics and, if resolved, would undoubtedly generate a new revolution in our understanding of the fundamental laws of Nature. The unprecedented and ever-growing experimental observations of gravitational waves, black holes, the cosmic microwave background, and elementary particles are promising to finally allow us to test the predictions of quantum gravity at observable scales. One promising approach to quantum gravity is inspired by string theory. A powerful nonperturbative description of string theory is given by the quantum mechanics of N × N matrices. At large N , it is famously conjectured that such a matrix quantum mechanics describes nonperturbative quantum gravity in 11 dimensions, which is known as M-theory. Matrix quantum mechanics is also related to Matrix gauge theories, which at large N correspond holographically to quantum gravity in emergent curved spacetime. Solving matrix quantum mechanics at large N promises a quantitative understanding of quantum gravity and black hole physics. This MSCA project attempts to gain new insights into M-theory and nonperturbative quantum gravity via a novel perspective that involves nonrelativistic behaviors. This project attempts to attack the following questions: Question 1: Is there a guiding principle for mapping out self-consistent limits of string theory? The success of such a formulation would allow us to enlarge the landscape of Matrix quantum mechanics and holographic duals between field theory and gravity. Patching up these different corners of string theory would eventually deepen our understanding of M-theory, in connection to Question 2 below. Question 2: M-theory has been mostly accessed via various corners where it is easier to understand their physical contents. What are the fundamental principles that one may use to define M-theory? Question 3: How insights from M-theory could be applied to understand puzzles in our observable universe? In order to address Question 1, this project builds around nonrelativistic string theory as a concrete starting point, where winding strings exchange instantaneous Newton-like interactions as it is for nonrelativistic particles. Based on my studies of extended objects (such as branes of various dimensions) in nonrelativistic string theory and their duals (i.e. two seemingly distinct theories are equivalent to each other), I connect nonrelativistic string theory to other important corners in string and M-theory, including matrix quantum mechanics and different holographic duals. I use this duality web to map out different decoupling nonperturbative corners of string and M-theory. For Question 2, I study the quantization of quantum critical membrane, which provides a candidate high-energy completion of the membrane in M-theory. Finally, in connection to Question 3, I also explore an application of M-theory to axion universe, which may provide new insights towards dark matter and the strong CP problem in particle physics and cosmology. The objective of this problem concerns the fundamental laws of physics. The holographical aspects have potential impacts on condensed matter physics.

Data: CORDIS, © European Union