scholarly journals SPIN-CUBE MODELS OF QUANTUM GRAVITY

2013 ◽  
Vol 25 (10) ◽  
pp. 1343008 ◽  
Author(s):  
A. MIKOVIĆ
Keyword(s):  
Models Of Quantum Gravity ◽  
Quantum Gravity ◽  
Path Integral ◽  
Classical Limit ◽  
Edge Length ◽  
The State ◽  
Regge Model ◽  
Bf Theory ◽  
Spin Foam Models ◽  
Spin Foam

We study the state-sum models of quantum gravity based on a representation 2-category of the Poincaré 2-group. We call them spin-cube models, since they are categorical generalizations of spin-foam models. A spin-cube state sum can be considered as a path integral for a constrained 2-BF theory, and depending on how the constraints are imposed, a spin-cube state sum can be reduced to a path integral for the area-Regge model with the edge-length constraints, or to a path integral for the Regge model. We also show that the effective actions for these spin-cube models have the correct classical limit.

scholarly journals GRAVITY AS BF THEORY PLUS POTENTIAL

2009 ◽  
Vol 24 (15) ◽  
pp. 2776-2782 ◽  
Author(s):  
KIRILL KRASNOV
Keyword(s):  
General Relativity ◽  
Models Of Quantum Gravity ◽  
Quantum Gravity ◽  
Alternative Formulation ◽  
Potential Term ◽  
Bf Theory ◽  
Spin Foam Models ◽  
Spin Foam ◽  
To Come

Spin foam models of quantum gravity are based on Plebanski's formulation of general relativity as a constrained BF theory. We give an alternative formulation of gravity as BF theory plus a certain potential term for the B-field. When the potential is taken to be infinitely steep one recovers general relativity. For a generic potential the theory still describes gravity in that it propagates just two graviton polarizations. The arising class of theories is of the type amenable to spin foam quantization methods, and, we argue, may allow one to come to terms with renormalization in the spin foam context.

scholarly journals NEW SPIN FOAM MODELS OF QUANTUM GRAVITY

2005 ◽  
Vol 20 (17n18) ◽  
pp. 1305-1313
Author(s):  
A. MIKOVIĆ
Keyword(s):  
General Relativity ◽  
Models Of Quantum Gravity ◽  
Quantum Gravity ◽  
Path Integral ◽  
Critical Review ◽  
Loop Quantum Gravity ◽  
Spin Networks ◽  
Spin Foam Models ◽  
Spin Foam Model ◽  
Spin Foam

We give a brief and a critical review of the Barret-Crane spin foam models of quantum gravity. Then we describe two new spin foam models which are obtained by direct quantization of General Relativity and do not have some of the drawbacks of the Barret-Crane models. These are the model of spin foam invariants for the embedded spin networks in loop quantum gravity and the spin foam model based on the integration of the tetrads in the path integral for the Palatini action.

scholarly journals q -deformed spin foam models of quantum gravity

2007 ◽  
Vol 24 (13) ◽  
pp. 3271-3290 ◽  
Author(s):  
Igor Khavkine ◽  
J Daniel Christensen
Keyword(s):  
Models Of Quantum Gravity ◽  
Quantum Gravity ◽  
Spin Foam Models ◽  
Spin Foam

scholarly journals MEASUREMENTS AND INFORMATION IN SPIN FOAM MODELS

2012 ◽  
Vol 27 (28) ◽  
pp. 1250164
Author(s):  
J. MANUEL GARCÍA-ISLAS
Keyword(s):  
Information Theory ◽  
Quantum Gravity ◽  
Cosmological Constant ◽  
Shannon Entropy ◽  
Three Dimensional ◽  
Spin Network ◽  
Spin Foam Models ◽  
Foam Model ◽  
Spin Foam Model ◽  
Spin Foam

In the three-dimensional spin foam model of quantum gravity with a cosmological constant, there exists a set of observables associated with spin network graphs. A set of probabilities is calculated from these observables, and hence the associated Shannon entropy can be defined. We present the Shannon entropy associated with these observables and find some interesting bounded inequalities. The problem relates measurements, entropy and information theory in a simple way which we explain.

scholarly journals Spin Foam Models with Finite Groups

2013 ◽  
Vol 2013 ◽  
pp. 1-28 ◽  
Author(s):  
Benjamin Bahr ◽  
Bianca Dittrich ◽  
James P. Ryan
Keyword(s):  
Field Theory ◽  
Quantum Gravity ◽  
Finite Groups ◽  
Loop Quantum Gravity ◽  
Theory Approach ◽  
Test Bed ◽  
Spin Foam Models ◽  
Spin Foam ◽  
Group Field Theory ◽  
The Many

Spin foam models, loop quantum gravity, and group field theory are discussed as quantum gravity candidate theories and usually involve a continuous Lie group. We advocate here to consider quantum gravity-inspired models with finite groups, firstly as a test bed for the full theory and secondly as a class of new lattice theories possibly featuring an analogue diffeomorphism symmetry. To make these notes accessible to readers outside the quantum gravity community, we provide an introduction to some essential concepts in the loop quantum gravity, spin foam, and group field theory approach and point out the many connections to the lattice field theory and the condensed-matter systems.

Sign in / Sign up

Export Citation Format

Share Document