QUANTUM CORRECTIONS EFFECT ON THE COUPLING OF THE GRAVITATIONAL AND SCALAR FIELDS AND SPONTANEOUSLY INDUCED GRAVITY

1989 ◽  
Vol 04 (05) ◽  
pp. 1223-1233 ◽  
Author(s):  
A. B. KAGANOVICH
Keyword(s):  
Gravitational Constant ◽  
Gauge Theories ◽  
Scalar Fields ◽  
Quantum Corrections ◽  
Zero Temperature ◽  
Nonminimal Coupling ◽  
Zero Energy ◽  
Induced Gravity ◽  
Loop Approximation ◽  
The One

Gravity induced by the spontaneous symmetry breaking in gauge theories is studied. All calculations are carried out with an accuracy provided by the one-loop approximation. It appears that in an effective potential of the scalar field φ a parameter ε of a nonminimal coupling of φ with a curvature is a function of φ. Under zero energy density of the stable vacuum <φ>0 = µ it is proved that the induced gravitational constant G ind is finite only if µε′(µ) = −2ε(µ). Hence it follows that if gravity is induced indeed then its theory necessarily has the structure of the Einstein's theory for gravitation: G ind is positive and invariable (at zero temperature). Within the limitations imposed by the model, the T-dependence of G ind is exponentially relaxed.

scholarly journals Harmonic Superspace Approach to the Effective Action in Six-Dimensional Supersymmetric Gauge Theories

Symmetry ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 68 ◽  
Author(s):  
Ioseph Buchbinder ◽  
Evgeny Ivanov ◽  
Boris Merzlikin ◽  
Konstantin Stepanyantz
Keyword(s):  
Effective Action ◽  
Gauge Theories ◽  
Proper Time ◽  
Background Field ◽  
Field Method ◽  
Quantum Corrections ◽  
Supersymmetric Gauge Theories ◽  
Loop Approximation ◽  
Supersymmetric Gauge ◽  
The One

We review the recent progress in studying the quantum structure of 6 D , N = ( 1 , 0 ) , and N = ( 1 , 1 ) supersymmetric gauge theories formulated through unconstrained harmonic superfields. The harmonic superfield approach allows one to carry out the quantization and calculations of the quantum corrections in a manifestly N = ( 1 , 0 ) supersymmetric way. The quantum effective action is constructed with the help of the background field method that secures the manifest gauge invariance of the results. Although the theories under consideration are not renormalizable, the extended supersymmetry essentially improves the ultraviolet behavior of the lowest-order loops. The N = ( 1 , 1 ) supersymmetric Yang–Mills theory turns out to be finite in the one-loop approximation in the minimal gauge. Furthermore, some two-loop divergences are shown to be absent in this theory. Analysis of the divergences is performed both in terms of harmonic supergraphs and by the manifestly gauge covariant superfield proper-time method. The finite one-loop leading low-energy effective action is calculated and analyzed. Furthermore, in the Abelian case, we discuss the gauge dependence of the quantum corrections and present its precise form for the one-loop divergent part of the effective action.

AN IMPROVED ONE-LOOP ANALYSIS OF THE λϕ4 THEORY AT FINITE TEMPERATURE

1987 ◽  
Vol 02 (03) ◽  
pp. 713-728 ◽  
Author(s):  
SWEE-PING CHIA
Keyword(s):  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
Zero Temperature ◽  
Coupling Constant ◽  
Loop Analysis ◽  
Temperature Dependent ◽  
Effective Coupling ◽  
Loop Approximation ◽  
The One ◽  
Dependent Mass

The λϕ4 theory with tachyonic mass is analyzed at T ≠ 0 using an improved one-loop approximation in which each of the bare propagators in the one-loop diagram is replaced by a dressed propagator to take into account the higher loop effects. The dressed propagator is characterized by a temperature-dependent mass which is determined by a self-consistent relation. Renomalization is found to be necessarily temperature-dependent. Real effective potential is obtained, giving rise to real effective mass and real coupling constant. For T < Tc, this is achieved by first shifting the ϕ field by its zero-temperature vacuum expectation value. The effective coupling constant is found to exhibit the striking behavior that it approaches a constant nonzero value as T → ∞.

scholarly journals PREPOTENTIALS OF N=2 SUPERSYMMETRIC GAUGE THEORIES AND SOLITON EQUATIONS

1996 ◽  
Vol 11 (02) ◽  
pp. 131-138 ◽  
Author(s):  
TOHRU EGUCHI ◽  
SUNG-KIL YANG
Keyword(s):  
Gauge Theories ◽  
Scalar Fields ◽  
Vector Multiplet ◽  
Coulomb Branch ◽  
Supersymmetric Gauge Theories ◽  
Expectation Values ◽  
Soliton Equations ◽  
Supersymmetric Gauge ◽  
Β Function ◽  
The One

Using recently proposed soliton equations we derive a basic identity for the scaling violation of N=2 supersymmetric gauge theories Σiai∂F/∂ai−2F=8πib1u. Here F is the prepotential, ai’s are the expectation values of the scalar fields in the vector multiplet, u=1/2 Tr<ϕ2> and b1 is the coefficient of the one-loop β-function. This equation holds in the Coulomb branch of all N=2 supersymmetric gauge theories coupled with massless matter.

scholarly journals On the component structure of one-loop effective actions in 6D, 𝒩 = (1,0) and 𝒩 = (1,1) supersymmetric gauge theories

2019 ◽  
Vol 35 (09) ◽  
pp. 2050060 ◽  
Author(s):  
I. L. Buchbinder ◽  
A. S. Budekhina ◽  
B. S. Merzlikin
Keyword(s):  
Effective Potential ◽  
Effective Action ◽  
Gauge Theories ◽  
Scalar Fields ◽  
Low Energy ◽  
Supersymmetric Gauge Theories ◽  
Component Structure ◽  
Yang Mills ◽  
Supersymmetric Gauge ◽  
The One

We study the six-dimensional [Formula: see text] and [Formula: see text] supersymmetric Yang–Mills (SYM) theories in the component formulation. The one-loop divergencies of effective action are calculated. The leading one-loop low-energy contributions to bosonic sector of effective action are found. It is explicitly demonstrated that the contributions to effective potential for the constant background scalar fields are absent in the [Formula: see text] SYM theory.

scholarly journals Application of a computer algebra systems to the calculation of the \(\pi\pi\)-scattering amplitude

2020 ◽  
Vol 28 (3) ◽  
pp. 216-229
Author(s):  
Yuriy L. Kalinovsky ◽  
Alexandra V. Friesen ◽  
Elizaveta D. Rogozhina ◽  
Lyubov’ I. Golyatkina
Keyword(s):  
Cross Section ◽  
Computer Algebra ◽  
Scattering Amplitude ◽  
Computer Algebra Systems ◽  
Zero Temperature ◽  
Feynman Integrals ◽  
Pion Scattering ◽  
Loop Approximation ◽  
Scattering Lengths ◽  
The One

The aim of this work is to develop a set of programs for calculation the scattering amplitudes of the elementary particles, as well as automating the calculation of amplitudes using the appropriate computer algebra systems (Mathematica, Form, Cadabra). The paper considers the process of pion-pion scattering in the framework of the effective Nambu-Iona-Lasinio model with two quark flavours. The Package-X for Mathematica is used to calculate the scattering amplitude (starting with the calculation of Feynman diagrams and ending with the calculation of Feynman integrals in the one-loop approximation). The loop integrals are calculated in general kinematics in Package-X using the Feynman parametrization technique. A simple check of the program is made: for the case with zero temperature, the scattering lengths \(a_0 = 0.147\) and \(a_2 = -0.0475\) are calculated and the total cross section is constructed. The results are compared with other models as well as with experimental data.

scholarly journals PHASE TRANSITION IN THE HIGGS MODEL OF SCALAR DYONS

2006 ◽  
Vol 21 (34) ◽  
pp. 2607-2619 ◽  
Author(s):  
C. R. DAS ◽  
L. V. LAPERASHVILI
Keyword(s):  
Phase Transition ◽  
Electric Charge ◽  
Scalar Fields ◽  
Higgs Model ◽  
Approximation Formula ◽  
Dual Symmetry ◽  
Loop Approximation ◽  
The One

In this paper we investigate the phase transition "Coulomb-confinement" in the Higgs model of Abelian scalar dyons – particles having both, electric e and magnetic g, charges. It is shown that by dual symmetry this theory is equivalent to scalar fields with the effective squared electric charge e*2 = e2+g2. But the Dirac relation distinguishes the electric and magnetic charges of dyons. The following phase transition couplings are obtained in the one-loop approximation: [Formula: see text], [Formula: see text] and [Formula: see text].

scholarly journals Covariant phase space and soft factorization in non-Abelian gauge theories

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Temple He ◽  
Prahar Mitra
Keyword(s):  
Phase Space ◽  
Ward Identity ◽  
Gauge Theories ◽  
Minkowski Spacetime ◽  
Soft Gluon ◽  
Careful Study ◽  
Abelian Gauge ◽  
Gauge Sector ◽  
Vacuum States ◽  
The One

Abstract We perform a careful study of the infrared sector of massless non-abelian gauge theories in four-dimensional Minkowski spacetime using the covariant phase space formalism, taking into account the boundary contributions arising from the gauge sector of the theory. Upon quantization, we show that the boundary contributions lead to an infinite degeneracy of the vacua. The Hilbert space of the vacuum sector is not only shown to be remarkably simple, but also universal. We derive a Ward identity that relates the n-point amplitude between two generic in- and out-vacuum states to the one computed in standard QFT. In addition, we demonstrate that the familiar single soft gluon theorem and multiple consecutive soft gluon theorem are consequences of the Ward identity.

scholarly journals Gauge theories on compact toric manifolds

2021 ◽  
Vol 111 (3) ◽  
Author(s):  
Giulio Bonelli ◽  
Francesco Fucito ◽  
Jose Francisco Morales ◽  
Massimiliano Ronzani ◽  
Ekaterina Sysoeva ◽  
...  
Keyword(s):  
Partition Function ◽  
Gauge Theories ◽  
Blow Up ◽  
Gauge Coupling ◽  
Piecewise Constant Function ◽  
Partition Functions ◽  
Piecewise Constant ◽  
Toric Manifolds ◽  
Holomorphic Anomaly ◽  
The One

AbstractWe compute the $$\mathcal{N}=2$$ N = 2 supersymmetric partition function of a gauge theory on a four-dimensional compact toric manifold via equivariant localization. The result is given by a piecewise constant function of the Kähler form with jumps along the walls where the gauge symmetry gets enhanced. The partition function on such manifolds is written as a sum over the residues of a product of partition functions on $$\mathbb {C}^2$$ C 2 . The evaluation of these residues is greatly simplified by using an “abstruse duality” that relates the residues at the poles of the one-loop and instanton parts of the $$\mathbb {C}^2$$ C 2 partition function. As particular cases, our formulae compute the SU(2) and SU(3) equivariant Donaldson invariants of $$\mathbb {P}^2$$ P 2 and $$\mathbb {F}_n$$ F n and in the non-equivariant limit reproduce the results obtained via wall-crossing and blow up methods in the SU(2) case. Finally, we show that the U(1) self-dual connections induce an anomalous dependence on the gauge coupling, which turns out to satisfy a $$\mathcal {N}=2$$ N = 2 analog of the $$\mathcal {N}=4$$ N = 4 holomorphic anomaly equations.

Sign in / Sign up

Export Citation Format

Share Document