scholarly journals Weak cosmic censorship with self-interacting scalar and bound on charge to mass ratio

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Yan Song ◽  
Tong-Tong Hu ◽  
Yong-Qiang Wang
Keyword(s):  
Scalar Field ◽  
Scalar Fields ◽  
Cosmic Censorship ◽  
Mass Ratio ◽  
Quartic Coupling ◽  
Scalar Theory ◽  
Free Scalar ◽  
The One ◽  
Nonzero Scalar ◽  
Large Charge

Abstract We study the model of four-dimensional Einstein-Maxwell-Λ theory minimally coupled to a massive charged self-interacting scalar field, parameterized by the quartic and hexic couplings, labelled by λ and β, respectively. In the absence of scalar field, there is a class of counterexamples to cosmic censorship. Moreover, we investigate the full nonlinear solution with nonzero scalar field included, and argue that these counterexamples can be removed by assuming charged self-interacting scalar field with sufficiently large charge not lower than a certain bound. In particular, this bound on charge required to preserve cosmic censorship is no longer precisely the weak gravity bound for the free scalar theory. For the quartic coupling, for λ < 0 the bound is below the one for the free scalar fields, whereas for λ > 0 it is above. Meanwhile, for the hexic coupling the bound is always above the one for the free scalar fields, irrespective of the sign of β.

scholarly journals Free Scalar Fields in Finite Volume Are Holographic

Universe ◽  
2019 ◽  
Vol 5 (12) ◽  
pp. 223
Author(s):  
Csaba Balázs
Keyword(s):  
Scalar Field ◽  
Surface Area ◽  
Finite Volume ◽  
Degrees Of Freedom ◽  
Scalar Fields ◽  
Flat Space ◽  
Linear Size ◽  
Energy Mode ◽  
Free Scalar ◽  
Quantized Field

This brief note presents a back-of-the-envelope calculation showing that the number of degrees of freedom of a free scalar field in expanding flat space equals the surface area of the Hubble volume in Planck units. The logic of the calculation is the following. The amount of energy in the Hubble volume scales with its linear size, consequently the volume can only contain a finite number of quantized field modes. Since the momentum of the lowest energy mode scales inversely with the linear size of the volume, the maximal number of such modes in the volume scales with its surface area. It is possible to show that when the number of field modes is saturated the modes are confined to the surface of the volume. Gravity only enters this calculation as a regulator, providing a finite volume that contains the field, the entire calculation is done in flat space. While this toy model is bound to be incomplete, it is potentially interesting because it reproduces the defining aspects of holography, and advocates a regularization of the quantum degrees of freedom based on Friedmann’s equation.

scholarly journals THE QUANTUM THEORY OF SCALAR FIELDS ON THE DE SITTER EXPANDING UNIVERSE

2008 ◽  
Vol 23 (16n17) ◽  
pp. 2563-2577 ◽  
Author(s):  
ION I. COTĂESCU ◽  
COSMIN CRUCEAN ◽  
ADRIAN POP
Keyword(s):  
Scalar Field ◽  
Gordon Equation ◽  
Scalar Fields ◽  
Wave Functions ◽  
De Sitter ◽  
Scalar Quantum ◽  
Long Time ◽  
Klein Gordon ◽  
Free Scalar ◽  
Special Time

New quantum modes of the free scalar field are derived in a special time-evolution picture that may be introduced in moving charts of de Sitter backgrounds. The wave functions of these new modes are solutions of the Klein–Gordon equation and energy eigenfunctions, defining the energy basis. This completes the scalar quantum mechanics where the momentum basis is well known for long time. In this enlarged framework the quantization of the scalar field can be done in canonical way obtaining the principal conserved one-particle operators and the Green functions.

scholarly journals ON FREE FIELD REALIZATIONS OF STRINGS IN BTZ

2004 ◽  
Vol 19 (10) ◽  
pp. 1579-1588 ◽  
Author(s):  
SAMULI HEMMING
Keyword(s):  
Scalar Field ◽  
Current Algebra ◽  
Free Field ◽  
Scalar Fields ◽  
Spectral Flow ◽  
Free Scalar ◽  
Discrete Representations ◽  
Continuous Representations

We discuss realizations of the SL (2,R) current algebra in the hyperbolic basis using free scalar fields. It has been previously shown by Satoh how such a realization can be used to describe the principal continuous representations of SL (2,R). We extend this work by introducing another realization that corresponds to the principal discrete representations of SL (2,R). We show that in these realizations spectral flow can be interpreted as twisting of a free scalar field. Finally, we discuss how these realizations can be obtained from the BTZ Lagrangian.

scholarly journals EFFECTIVE POTENTIAL FOR LIFSHITZ-TYPE z = 3 GAUGE THEORIES

2012 ◽  
Vol 27 (29) ◽  
pp. 1250168 ◽  
Author(s):  
K. FARAKOS
Keyword(s):  
Scalar Field ◽  
Symmetry Breaking ◽  
Effective Potential ◽  
Local Minimum ◽  
Relative Strength ◽  
Coupling Constants ◽  
Time Scaling ◽  
Symmetry Breaking Term ◽  
The One ◽  
Nonzero Scalar

We consider the one-loop effective potential at zero temperature in Lifshitz-type field theories with anisotropic space–time scaling, with critical exponent z = 3, including scalar, fermion and gauge fields. The fermion determinant generates a symmetry breaking term at one loop in the effective potential and a local minimum appears, for nonzero scalar field, for every value of the Yukawa coupling. Depending on the relative strength of the coupling constants for the scalar and the gauge field, we find a second symmetry breaking local minimum in the effective potential for a bigger value of the scalar field.

scholarly journals SELF-INTERACTING SCALAR FIELDS ON SPACE-TIME WITH COMPACT HYPERBOLIC SPATIAL PART

1993 ◽  
Vol 08 (21) ◽  
pp. 2011-2021 ◽  
Author(s):  
ANDREI BYTSENKO ◽  
KLAUS KIRSTEN ◽  
SERGEI ODINTSOV
Keyword(s):  
Phase Transitions ◽  
Scalar Field ◽  
Effective Potential ◽  
Discrete Group ◽  
Scalar Fields ◽  
Space Time ◽  
Selberg Trace Formula ◽  
Effective Potentials ◽  
Spatial Part ◽  
The One

We calculate the one-loop effective potential of a self-interacting scalar field on the space-time of the form ℝ2×H2/Γ. The Selberg trace formula associated with a co-compact discrete group Γ in PSL(2, ℝ) (hyperbolic and elliptic elements only) is used. The closed form for the one-loop unrenormalized and renormalized effective potentials is given. The influence of non-trivial topology on curvature induced phase transitions is also discussed.

scholarly journals Noncommutativity in Effective Loop Quantum Cosmology

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Abraham Espinoza-García ◽  
Efraín Torres-Lomas ◽  
Sinuhé Pérez-Payán ◽  
Luis Rey Díaz-Barrón
Keyword(s):  
Scalar Field ◽  
Quantum Cosmology ◽  
Free Field ◽  
Matter Field ◽  
Field Energy ◽  
Loop Quantum Cosmology ◽  
Free Scalar ◽  
Key Features ◽  
Field Energy Density ◽  
The One

We construct a noncommutative extension of the Loop Quantum Cosmology effective scheme for the flat FLRW model with a free scalar field via a theta deformation. Firstly, a deformation is implemented in the configuration sector, among the holonomy variable and the matter degree of freedom. We show that this type of noncommutativity retains, to some degree, key features of the Loop Quantum Cosmology paradigm for a free field. Secondly, a deformation is implemented in the momentum sector, among the momentum associated with the holonomy variable and the momentum associated with the matter field. We show that in this latter case the scalar field energy density is the same as the one in standard Loop Quantum Cosmology.

scholarly journals LINE DISCONTINUITIES, LOCAL ACTION WITH BOTH THE FIELD AND ITS DUAL, AND SPIN FROM NO SPIN IN TWO-DIMENSIONAL SCALAR THEORY

2013 ◽  
Vol 28 (01) ◽  
pp. 1350003
Author(s):  
CHANDRASEKHAR CHATTERJEE ◽  
E. HARIKUMAR ◽  
MANU MATHUR ◽  
INDRAJIT MITRA ◽  
H. S. SHARATCHANDRA
Keyword(s):  
Scalar Field ◽  
Scalar Fields ◽  
Local Action ◽  
Singular Line ◽  
Two Dimensional ◽  
Scalar Theory ◽  
The Real ◽  
Real Scalar ◽  
Wick’S Theorem

We consider a local action with both the real scalar field and its dual in two Euclidean dimensions. The role of singular line discontinuities is emphasized. Exotic properties of the correlation of the field with its dual, the generation of spin from scalar fields, and quantization of dual charges are pointed out. Wick's theorem and rotation properties of fermions are recovered for half-integer quantization.

PATH INTEGRALS AND THE TRACE ANOMALY IN A SELF-INTERACTING SCALAR THEORY

1989 ◽  
Vol 04 (02) ◽  
pp. 155-159 ◽  
Author(s):  
M. S. ALVES ◽  
J. BARCELOS-NETO
Keyword(s):  
Scalar Field ◽  
Path Integral ◽  
Integral Method ◽  
Path Integrals ◽  
Scalar Fields ◽  
Scalar Theory ◽  
Trace Anomaly ◽  
Path Integral Method

We calculate the trace anomaly for massless self-interacting scalar fields propagating on a gravitational and a scalar field background. This is done by using Fujikawa's path integral method.

scholarly journals FERMIONIC AND SCALAR FIELDS AS SOURCES OF INTERACTING DARK MATTER–DARK ENERGY

2011 ◽  
Vol 20 (13) ◽  
pp. 2543-2558 ◽  
Author(s):  
SAMUEL LEPE ◽  
JAVIER LORCA ◽  
FRANCISCO PEÑA ◽  
YERKO VÁSQUEZ
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Scalar Field ◽  
Analytical Solution ◽  
Scalar Fields ◽  
Nonminimal Coupling ◽  
Field Equations ◽  
Fermionic Field ◽  
Minimal Coupling ◽  
Constant Type

From a variational action with nonminimal coupling with a scalar field and classical scalar and fermionic interaction, cosmological field equations can be obtained. Imposing a Friedmann–Lemaître–Robertson–Walker (FLRW) metric, the equations lead directly to a cosmological model consisting of two interacting fluids, where the scalar field fluid is interpreted as dark energy and the fermionic field fluid is interpreted as dark matter. Several cases were studied analytically and numerically. An important feature of the non-minimal coupling is that it allows crossing the barrier from a quintessence to phantom behavior. The insensitivity of the solutions to one of the parameters of the model permits it to find an almost analytical solution for the cosmological constant type of universe.

Sign in / Sign up

Export Citation Format

Share Document