Signature change of the metric in CDT quantum gravity?

被引：25

作者：

Ambjorn, J. ^{[1
,2
]}

Coumbe, D. N. ^{[2
]}

Gizbert-Studnicki, J. ^{[2
]}

Jurkiewicz, J. ^{[2
]}

机构：

[1] Univ Copenhagen, Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen, Denmark

[2] Jagiellonian Univ, Fac Phys Astron & Appl Comp Sci, PL-30348 Krakow, Poland

来源：

JOURNAL OF HIGH ENERGY PHYSICS | 2015年 / 08期

关键词：

Models of Quantum Gravity; Lattice Models of Gravity; ULTRAVIOLET PROPERTIES;

D O I：

10.1007/JHEP08(2015)033

中图分类号：

O412 [相对论、场论]; O572.2 [粒子物理学];

学科分类号：

摘要：

We study the effective transfer matrix within the semiclassical and bifurcation phases of CDT quantum gravity. We find that for sufficiently large lattice volumes the kinetic term of the effective transfer matrix has a different sign in each of the two phases. We argue that this sign change can be viewed as a Wick rotation of the metric. We discuss the likely microscopic mechanism responsible for the bifurcation phase transition, and propose an order parameter that can potentially be used to determine the precise location and order of the transition. Using the effective transfer matrix we approximately locate the position of the bifurcation transition in some region of coupling constant space, allowing us to present an updated version of the CDT phase diagram.

引用

页数：17

共 27 条

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