TY - JOUR

T1 - CDT Quantum Toroidal Spacetimes

T2 - An Overview

AU - Ambjorn, Jan

AU - Drogosz, Zbigniew

AU - Gizbert-Studnicki, Jakub

AU - Gorlich, Andrzej

AU - Jurkiewicz, Jerzy

AU - Nemeth, Daniel

PY - 2021/3/26

Y1 - 2021/3/26

N2 - Lattice formulations of gravity can be used to study non-perturbative aspects of quantum gravity. Causal Dynamical Triangulations (CDT) is a lattice model of gravity that has been used in this way. It has a built-in time foliation but is coordinate-independent in the spatial directions. The higher-order phase transitions observed in the model may be used to define a continuum limit of the lattice theory. Some aspects of the transitions are better studied when the topology of space is toroidal rather than spherical. In addition, a toroidal spatial topology allows us to understand more easily the nature of typical quantum fluctuations of the geometry. In particular, this topology makes it possible to use massless scalar fields that are solutions to Laplace's equation with special boundary conditions as coordinates that capture the fractal structure of the quantum geometry. When such scalar fields are included as dynamical fields in the path integral, they can have a dramatic effect on the geometry.

AB - Lattice formulations of gravity can be used to study non-perturbative aspects of quantum gravity. Causal Dynamical Triangulations (CDT) is a lattice model of gravity that has been used in this way. It has a built-in time foliation but is coordinate-independent in the spatial directions. The higher-order phase transitions observed in the model may be used to define a continuum limit of the lattice theory. Some aspects of the transitions are better studied when the topology of space is toroidal rather than spherical. In addition, a toroidal spatial topology allows us to understand more easily the nature of typical quantum fluctuations of the geometry. In particular, this topology makes it possible to use massless scalar fields that are solutions to Laplace's equation with special boundary conditions as coordinates that capture the fractal structure of the quantum geometry. When such scalar fields are included as dynamical fields in the path integral, they can have a dramatic effect on the geometry.

KW - quantum gravity

KW - lattice quantum field theory

KW - dynamical triangulations

KW - emergent spacetime

KW - FRACTAL STRUCTURE

KW - BABY UNIVERSES

KW - GRAVITY

KW - TRIANGULATIONS

KW - 2D

U2 - 10.3390/universe7040079

DO - 10.3390/universe7040079

M3 - Review

VL - 7

JO - Universe

JF - Universe

SN - 2218-1997

IS - 4

M1 - 79

ER -