scholarly journals Some solutions for one of the cosmological constant problems

2016 ◽  
Vol 31 (37) ◽  
pp. 1650213 ◽  
Author(s):  
Shin’ichi Nojiri
Keyword(s):  
Cosmological Constant ◽  
Topological Field Theories ◽  
Vacuum Energy ◽  
Gravity Models ◽  
Field Theories ◽  
Quantum Corrections ◽  
Covariant Formulation ◽  
Gravitational Action ◽  
Topological Field ◽  
Brs Symmetry

We propose several covariant models which may solve one of the problems in the cosmological constant. One of the models can be regarded as an extension of sequestering model. Other models could be regarded as extensions of the covariant formulation of the unimodular gravity. The contributions to the vacuum energy from the quantum corrections from the matters are absorbed into a redefinition of a scalar field and the quantum corrections become irrelevant to the dynamics. In a class of the extended unimodular gravity models, we also consider models which are regarded as topological field theories. The models can be extended and not only the vacuum energy but also any quantum corrections to the gravitational action could become irrelevant for the dynamics. We find, however, that the BRS symmetry in the topological field theories is broken spontaneously and therefore, the models might not be consistent.

scholarly journals EXTENDED BRS SYMMETRY IN TOPOLOGICAL FIELD THEORIES

2008 ◽  
Vol 23 (14) ◽  
pp. 993-998
Author(s):  
P. VALTANCOLI
Keyword(s):  
Topological Field Theories ◽  
Landau Gauge ◽  
Field Theories ◽  
Simons Theory ◽  
Gauge Fixing ◽  
Topological Field ◽  
New Type ◽  
Chern Simons ◽  
Brs Symmetry ◽  
Chern Simons Theory

A class of topological field theories like the BF model and Chern–Simons theory, when quantized in the Landau gauge, enjoys the property of invariance under a vector supersymmetry, which is responsible for their finiteness. We introduce a new type of gauge fixing which makes these theories invariant under an extended BRS symmetry, containing a new type of field, the ghost of diffeomorphisms. The presence of such an extension is naturally related to the vector supersymmetry discussed before.

A COMMENT ON TOPOLOGICAL FIELD THEORY QUANTIZATION AND STOCHASTIC PROCESSES

1990 ◽  
Vol 05 (19) ◽  
pp. 3777-3786 ◽  
Author(s):  
L.F. CUGLIANDOLO ◽  
G. LOZANO ◽  
H. MONTANI ◽  
F.A. SCHAPOSNIK
Keyword(s):  
Field Theory ◽  
Equilibrium State ◽  
Stochastic Processes ◽  
Topological Field Theories ◽  
Topological Charge ◽  
Field Theories ◽  
Langevin Equations ◽  
Topological Field Theory ◽  
Topological Field

We discuss the relation between different quantization approaches to topological field theories by deriving a connection between Bogomol’nyi and Langevin equations for stochastic processes which evolve towards an equilibrium state governed by the topological charge.

scholarly journals Topological field theories on manifolds with Wu structures

2017 ◽  
Vol 29 (05) ◽  
pp. 1750015 ◽  
Author(s):  
Samuel Monnier
Keyword(s):  
Topological Field Theories ◽  
Geometric Quantization ◽  
Discrete Symmetry ◽  
Local System ◽  
Field Theories ◽  
Simons Theory ◽  
General Point ◽  
Topological Field ◽  
Generalized Cohomology ◽  
Chern Simons

We construct invertible field theories generalizing abelian prequantum spin Chern–Simons theory to manifolds of dimension [Formula: see text] endowed with a Wu structure of degree [Formula: see text]. After analyzing the anomalies of a certain discrete symmetry, we gauge it, producing topological field theories whose path integral reduces to a finite sum, akin to Dijkgraaf–Witten theories. We take a general point of view where the Chern–Simons gauge group and its couplings are encoded in a local system of integral lattices. The Lagrangian of these theories has to be interpreted as a class in a generalized cohomology theory in order to obtain a gauge invariant action. We develop a computationally friendly cochain model for this generalized cohomology and use it in a detailed study of the properties of the Wu Chern–Simons action. In the 3-dimensional spin case, the latter provides a definition of the “fermionic correction” introduced recently in the literature on fermionic symmetry protected topological phases. In order to construct the state space of the gauged theories, we develop an analogue of geometric quantization for finite abelian groups endowed with a skew-symmetric pairing. The physical motivation for this work comes from the fact that in the [Formula: see text] case, the gauged 7-dimensional topological field theories constructed here are essentially the anomaly field theories of the 6-dimensional conformal field theories with [Formula: see text] supersymmetry, as will be discussed elsewhere.

scholarly journals QUANTUM CORRECTIONS TO GRAVITY AND THEIR IMPLICATIONS FOR COSMOLOGY AND ASTROPHYSICS

2012 ◽  
Vol 14 ◽  
pp. 73-87 ◽  
Author(s):  
JULIO C. FABRIS ◽  
PAULO L. C. DE OLIVEIRA ◽  
DAVI C. RODRIGUES ◽  
ALAN M. VELASQUEZ-TORIBIO ◽  
ILYA L. SHAPIRO
Keyword(s):  
Cosmological Constant ◽  
Free Parameter ◽  
Quantum Correction ◽  
Functional Form ◽  
Quantum Corrections ◽  
Inflationary Cosmology ◽  
Gravitational Action ◽  
Higher Derivative ◽  
Hilbert Action

The quantum contributions to the gravitational action are relatively easy to calculate in the higher derivative sector of the theory. However, the applications to the post-inflationary cosmology and astrophysics require the corrections to the Einstein-Hilbert action and to the cosmological constant, and those we can not derive yet in a consistent and safe way. At the same time, if we assume that these quantum terms are covariant and that they have relevant magnitude, their functional form can be defined up to a single free parameter, which can be defined on the phenomenological basis. It turns out that the quantum correction may lead, in principle, to surprisingly strong and interesting effects in astrophysics and cosmology .

The Vilkovisky-De Witt effective action in BF-type topological field theories

1991 ◽  
Vol 269 (1-2) ◽  
pp. 116-122 ◽  
Author(s):  
Danny Birmingham ◽  
H.T. Cho ◽  
R. Kantowski ◽  
M. Rakowski
Keyword(s):  
Topological Field Theories ◽  
Effective Action ◽  
Field Theories ◽  
Topological Field
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