scholarly journals ARE THERE ANY NEW VACUA OF GAUGED ${\mathcal N}=8$ SUPERGRAVITY IN FOUR DIMENSIONS?

2010 ◽  
Vol 25 (09) ◽  
pp. 1819-1851 ◽  
Author(s):  
CHANGHYUN AHN ◽  
KYUNGSUNG WOO
Keyword(s):  
Domain Wall ◽  
Cosmological Constant ◽  
Critical Point ◽  
Scalar Potential ◽  
Three Dimensional ◽  
Scalar Fields ◽  
Four Dimensions ◽  
Matter Theory ◽  
Chern Simons ◽  
Constraint Surface

We consider the most general SU(3) singlet space of gauged [Formula: see text] supergravity in four dimensions. The SU(3)-invariant six scalar fields in the theory can be viewed in terms of six real four-forms. By exponentiating these four-forms, we eventually obtain the new scalar potential. For the two extreme limits, we reproduce the previous results found by Warner in 1983. In particular, for the [Formula: see text] critical point, we find the constraint surface parametrized by three scalar fields on which the cosmological constant has the same value. We obtain the BPS domain-wall solutions for restricted scalar submanifold. We also describe the three-dimensional mass-deformed superconformal Chern–Simons matter theory dual to the above supersymmetric flows in four dimensions.

scholarly journals Three-dimensional Maxwellian extended Newtonian gravity and flat limit

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Patrick Concha ◽  
Lucrezia Ravera ◽  
Evelyn Rodríguez ◽  
Gustavo Rubio
Keyword(s):  
Cosmological Constant ◽  
Three Dimensional ◽  
Expansion Method ◽  
Gravity Models ◽  
Newtonian Gravity ◽  
Newtonian Theory ◽  
Relativistic Limit ◽  
Expansion Procedure ◽  
Three Space ◽  
Chern Simons

Abstract In the present work we find novel Newtonian gravity models in three space-time dimensions. We first present a Maxwellian version of the extended Newtonian gravity, which is obtained as the non-relativistic limit of a particular U(1)-enlargement of an enhanced Maxwell Chern-Simons gravity. We show that the extended Newtonian gravity appears as a particular sub-case. Then, the introduction of a cosmological constant to the Maxwellian extended Newtonian theory is also explored. To this purpose, we consider the non-relativistic limit of an enlarged symmetry. An alternative method to obtain our results is presented by applying the semigroup expansion method to the enhanced Nappi-Witten algebra. The advantages of considering the Lie algebra expansion procedure is also discussed.

scholarly journals ON WEYL COSMOLOGY IN FIVE DIMENSIONS AND THE COSMOLOGICAL CONSTANT

2009 ◽  
Vol 24 (08n09) ◽  
pp. 1505-1509 ◽  
Author(s):  
JOSE EDGAR MADRIZ AGUILAR ◽  
CARLOS ROMERO
Keyword(s):  
Cosmological Constant ◽  
Energy Momentum Tensor ◽  
Constant Term ◽  
Momentum Tensor ◽  
Five Dimensions ◽  
Four Dimensions ◽  
Riemannian Spacetime ◽  
Matter Theory ◽  
Induced Matter ◽  
Weyl Scalar

In this talk notes we expose the possibility to induce the cosmological constant from extra dimensions from a geometrical framework where our four-dimensional Riemannian spacetime is embedded into a five-dimensional Weyl integrable space. In particular following the approach of the induced matter theory (IMT) we show that when we go down from five to four dimensions we may recover the induced energy momentum tensor of the IMT plus a cosmological constant term that is determined by the presence of the Weyl scalar field on the bulk.

COSMOLOGY WITH NEGATIVE POTENTIALS WITH wϕ<-1

2004 ◽  
Vol 13 (09) ◽  
pp. 1939-1953 ◽  
Author(s):  
A. DE LA MACORRA ◽  
G. GERMÁN
Keyword(s):  
Equation Of State ◽  
Energy Density ◽  
Cosmological Constant ◽  
Particle Physics ◽  
Scalar Potential ◽  
Energy Condition ◽  
State Parameter ◽  
Scalar Fields ◽  
High Energy ◽  
Equation Of State Parameter

We study the cosmology of canonically normalized scalar fields that lead to an equation of state parameter of wϕ=pϕ/ρϕ<-1 without violating the weak energy condition: ρ=Σiρi≥0 and ρi+pi≥0. This kind of behavior requires a negative scalar potential V, widely predicted in particle physics. We show that the energy density ρϕ=Ek+V takes negative values with an equation of state with wϕ<-1. However, the net effect of the ϕ field on the scale factor is to decelerate it giving a total equation of state parameter w=p/ρ>wb=pb/ρb, where ρb stands for any kind of energy density with -1≤wb≤1, such as radiation, matter, cosmological constant or other scalar field with a potential V≥0. The fact that ρϕ<0 allows, at least in principle, to have a small cosmological constant or quintessence today as the cancellation of high energy scales such as the electroweak or susy breaking scale. While V is negative |ρϕ| is smaller than the sum of all other energy densities regardless of the functional form of the potential V. We show that the existence of a negative potential leads, inevitable, to a collapsing universe, i.e. to a would be "big crunch." In this picture we would still be living in the expanding universe.

scholarly journals ${\mathcal N}=8$ GAUGED SUPERGRAVITY THEORY AND ${\mathcal N}=6$ SUPERCONFORMAL CHERN–SIMONS MATTER THEORY

2010 ◽  
Vol 25 (17) ◽  
pp. 3407-3444 ◽  
Author(s):  
CHANGHYUN AHN ◽  
KYUNGSUNG WOO
Keyword(s):  
Renormalization Group ◽  
Renormalization Group Flow ◽  
Supergravity Theory ◽  
Four Dimensions ◽  
Probe Analysis ◽  
Matter Theory ◽  
Mass Terms ◽  
Group Flow ◽  
Chern Simons

By studying the previously known holographic [Formula: see text] supersymmetric renormalization group flow (Gowdigere–Warner) in four dimensions, we find the mass deformed Chern–Simons matter theory which has [Formula: see text] supersymmetry by adding the four mass terms among eight adjoint fields. The geometric superpotential from the 11 dimensions is found and provides the M2-brane probe analysis. As second example, we consider known holographic [Formula: see text] supersymmetric renormalization group flow (Pope–Warner) in four dimensions. The eight mass terms are added and similar geometric superpotential is obtained.

scholarly journals Three-dimensional teleparallel Chern-Simons supergravity theory

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Ricardo Caroca ◽  
Patrick Concha ◽  
Diego Peñafiel ◽  
Evelyn Rodríguez
Keyword(s):  
Cosmological Constant ◽  
Riemannian Geometry ◽  
Three Dimensional ◽  
Supersymmetric Extension ◽  
Supergravity Theory ◽  
Gauge Invariant ◽  
Poincaré Algebra ◽  
Chern Simons

AbstractIn this work we present a gauge-invariant three-dimensional teleparallel supergravity theory using the Chern-Simons formalism. The present construction is based on a supersymmetric extension of a particular deformation of the Poincaré algebra. At the bosonic level the theory describes a non-Riemannian geometry with a non-vanishing torsion. In presence of supersymmetry, the teleparallel supergravity theory is characterized by a non-vanishing super-torsion in which the cosmological constant can be seen as a source for the torsion. We show that the teleparallel supergravity theory presented here reproduces the Poincaré supergravity in the vanishing cosmological limit. The extension of our results to $${\mathcal {N}}=p+q$$ N = p + q supersymmetries is also explored.

scholarly journals Cosmological Constant from Condensation of Defect Excitations

Universe ◽  
2018 ◽  
Vol 4 (7) ◽  
pp. 81 ◽  
Author(s):  
Bianca Dittrich
Keyword(s):  
Hilbert Space ◽  
Quantum Gravity ◽  
Cosmological Constant ◽  
Quantum Cosmology ◽  
Condensed Matter ◽  
Three Dimensional ◽  
Class Constraint ◽  
Four Dimensions ◽  
Dimensional Gravity ◽  
Constraint Algebra

A key challenge for many quantum gravity approaches is to construct states that describe smooth geometries on large scales. Here we define a family of (2+1)-dimensional quantum gravity states which arise from curvature excitations concentrated at point like defects and describe homogeneously curved geometries on large scales. These states represent therefore vacua for three-dimensional gravity with different values of the cosmological constant. They can be described by an anomaly-free first class constraint algebra quantized on one and the same Hilbert space for different values of the cosmological constant. A similar construction is possible in four dimensions, in this case the curvature is concentrated along string-like defects and the states are vacua of the Crane-Yetter model. We will sketch applications for quantum cosmology and condensed matter.

DE SITTER GRAVITY AND SUPERGRAVITY IN THREE DIMENSIONS AS CHERN-SIMONS THEORIES

1990 ◽  
Vol 05 (12) ◽  
pp. 935-941 ◽  
Author(s):  
K. KOEHLER ◽  
F. MANSOURI ◽  
CENALO VAZ ◽  
L. WITTEN
Keyword(s):  
Gauge Theory ◽  
Cosmological Constant ◽  
Classical Theory ◽  
Three Dimensional ◽  
Three Dimensions ◽  
De Sitter ◽  
Positive Cosmological Constant ◽  
Supergravity Theory ◽  
Gauge Transformations ◽  
Chern Simons

We construct a de Sitter supergravity theory in 2 + 1 dimensions as the Chern-Simons gauge theory of the supergroup OSp (1|2; C). The resulting action is a consistent classical supergravity theory with a positive cosmological constant. As in other three dimensional Chern-Simons theories, diffeomorphisms are shown to be equivalent to gauge transformations of OSp (1|2; C) on shell. Consistency of the corresponding classical theory is briefly discussed.

scholarly journals Three-dimensional noncommutative Yukawa theory: Induced effective action and propagating modes

2017 ◽  
Vol 32 (04) ◽  
pp. 1750019 ◽  
Author(s):  
R. Bufalo ◽  
M. Ghasemkhani
Keyword(s):  
Three Dimensional ◽  
Scalar Fields ◽  
Gauge Fields ◽  
Polarization Tensor ◽  
Charged Scalar ◽  
Self Energy ◽  
Charged Scalar Field ◽  
The One ◽  
Chern Simons ◽  
Yukawa Theory

In this paper, we establish the analysis of noncommutative Yukawa theory, encompassing neutral and charged scalar fields. We approach the analysis by considering carefully the derivation of the respective effective actions. Hence, based on the obtained results, we compute the one-loop contributions to the neutral and charged scalar field self-energy, as well as to the Chern–Simons polarization tensor. In order to properly define the behavior of the quantum fields, the known UV/IR mixing due to radiative corrections is analyzed in the one-loop physical dispersion relation of the scalar and gauge fields.

CANONICAL QUANTIZATION OF BIANCHI CLASS A MODELS IN N=2 SUPERGRAVITY

1996 ◽  
Vol 11 (03) ◽  
pp. 227-245 ◽  
Author(s):  
A.D.Y. CHENG ◽  
P.V. MONIZ
Keyword(s):  
Cosmological Constant ◽  
Canonical Quantization ◽  
Constant Term ◽  
Scalar Fields ◽  
Internal Symmetry ◽  
Point Of View ◽  
Supergravity Theory ◽  
Class A ◽  
Physical Validity ◽  
Chern Simons

The theory of N=2 supergravity is applied to Bianchi class A models. Their canonical formulation is addressed for two cases: when the O(2) internal symmetry is (a) global or (b) local. A cosmological constant and mass-like term for the gravitinos are required in the latter but are absent in the former. For the case of global O(2) symmetry, it is shown that the presence of a Maxwell field in the supersymmetry constraints is sufficient to imply a non-conservation of the fermionic number. This effect corresponds to a mixing between different Lorentz invariant fermionic sectors in the wave function of the universe. It is similar to what a cosmological constant term would have caused but considerably different from what occurs in FRW and Bianchi models in N=1 supergravity with scalar fields and fermionic partners. The nonconservation effect is interpreted from the point of view of N=2 supergravity theory. For case (b), we obtain the more general solution of the gauge constraint. Possible quantum physical states are then discussed regarding previous works where Ashtekar variables have been used. These states can be obtained from an N=2 supersymmetric Chern-Simons functional. Some comments concerning the physical validity of the Chern-Simons solution and its transformation into metric representation variables are included.

scholarly journals Effective theories and non-minimal couplings in low-dimensional systems

2021 ◽  
pp. 2150099
Author(s):  
M. G. Campos ◽  
L. P. R. Ospedal
Keyword(s):  
Three Dimensional ◽  
Three Dimensions ◽  
Minimal Coupling ◽  
Four Dimensions ◽  
Dimensional Spacetime ◽  
External Electromagnetic Fields ◽  
Fermionic Fields ◽  
Low Dimensional ◽  
Effective Theories ◽  
Chern Simons

Dimensionality aspects of non-minimal electromagnetic couplings are investigated. By means of the Foldy–Wouthuysen transformation, we attain (non-)relativistic interactions related to the non-minimal coupling in three-dimensional spacetime, for both the bosonic and fermionic fields. Next, we establish some comparisons and analyze particular situations in which the external electromagnetic fields are described either by Maxwell or Maxwell–Chern–Simons Electrodynamics. In addition, we consider the situation of a non-minimal coupling for the fermionic field in four dimensions, carry out its dimensional reduction to three dimensions and show that the three-dimensional scenario previously worked out can be recovered as a particular case. Finally, we discuss a number of structural aspects of both procedures.

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