Stereoelectronic Interactions and the One-Bond C–F Coupling Constant in Sevoflurane

2012 ◽  
Vol 116 (6) ◽  
pp. 1677-1682 ◽  
Author(s):  
Matheus P. Freitas ◽  
Michael Bühl ◽  
David O’Hagan ◽  
Rodrigo A. Cormanich ◽  
Cláudio F. Tormena
Keyword(s):  
Coupling Constant ◽  
The One ◽  
Stereoelectronic Interactions

scholarly journals Supergraph calculation of one-loop divergences in higher-derivative 6D SYM theory

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
I. L. Buchbinder ◽  
E. A. Ivanov ◽  
B. S. Merzlikin ◽  
K. V. Stepanyantz
Keyword(s):  
Effective Action ◽  
A Priori ◽  
Coupling Constant ◽  
Harmonic Superspace ◽  
Classical Action ◽  
Higher Derivative ◽  
Component Approach ◽  
Dimensionless Coupling ◽  
The One ◽  
Dimensionless Coupling Constant

Abstract We apply the harmonic superspace approach for calculating the divergent part of the one-loop effective action of renormalizable 6D, $$ \mathcal{N} $$ N = (1, 0) supersymmetric higher-derivative gauge theory with a dimensionless coupling constant. Our consideration uses the background superfield method allowing to carry out the analysis of the effective action in a manifestly gauge covariant and $$ \mathcal{N} $$ N = (1, 0) supersymmetric way. We exploit the regularization by dimensional reduction, in which the divergences are absorbed into a renormalization of the coupling constant. Having the expression for the one-loop divergences, we calculate the relevant β-function. Its sign is specified by the overall sign of the classical action which in higher-derivative theories is not fixed a priori. The result agrees with the earlier calculations in the component approach. The superfield calculation is simpler and provides possibilities for various generalizations.

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 WORLDLINE VARIATIONAL APPROXIMATION: A NEW APPROACH TO THE RELATIVISTIC BINDING PROBLEM

2005 ◽  
Vol 20 (33) ◽  
pp. 2533-2543 ◽  
Author(s):  
K. BARRO-BERGFLÖDT ◽  
R. ROSENFELDER ◽  
M. STINGL
Keyword(s):  
Bound State ◽  
Equal Mass ◽  
Variational Approximation ◽  
Coupling Constant ◽  
Critical Coupling ◽  
Heavy Particles ◽  
Self Energy ◽  
Quantitative Changes ◽  
The One ◽  
Traditional Approaches

We determine the lowest bound-state pole of the density–density correlator in the scalar Wick–Cutkosky model where two equal-mass constituents interact via the exchange of mesons. This is done by employing the worldline representation of field theory together with a variational approximation as in Feynman's treatment of the polaron. Unlike traditional methods based on the Bethe–Salpeter equation, self-energy and vertex corrections are (approximately) included as are crossed diagrams. Only vacuum-polarization effects of the heavy particles are neglected. The well-known instability of the model due to self-energy effects leads to large qualitative and quantitative changes compared to traditional approaches which neglect them. We determine numerically the critical coupling constant above which no real solutions of the variational equations exist anymore and show that it is smaller than in the one-body case due to an induced instability. The width of the bound state above the critical coupling is estimated analytically.

scholarly journals Spinor field in Bianchi type-IX space–time

2018 ◽  
Vol 96 (10) ◽  
pp. 1074-1084
Author(s):  
Bijan Saha
Keyword(s):  
Spinor Field ◽  
Bianchi Type ◽  
Energy Momentum Tensor ◽  
Early Stage ◽  
Momentum Tensor ◽  
Space Time ◽  
Rapid Expansion ◽  
Coupling Constant ◽  
The One

Within the scope of Bianchi type-IX cosmological model we have studied the role of spinor field in the evolution of the Universe. It is found that unlike the diagonal Bianchi models in this case the components of energy–momentum tensor of spinor field along the principal axis are not the same (i.e., [Formula: see text]), even in the absence of spinor field nonlinearity. The presence of nontrivial non-diagonal components of energy–momentum tensor of the spinor field imposes severe restrictions both on geometry of space–time and on the spinor field itself. As a result the space–time turns out to be either locally rotationally symmetric or isotropic. In this paper we considered the Bianchi type-IX space–time both for a trivial b, that corresponds to standard Bianchi type-IX and the one with a non-trivial b. It was found that a positive self-coupling constant λ1 gives rise to an oscillatory mode of expansion, while a trivial λ1 leads to rapid expansion at the early stage of evolution.

scholarly journals COMPLETE CLASSES OF GUTS WITH VANISHING ONE-LOOP BETA FUNCTIONS

1994 ◽  
Vol 09 (29) ◽  
pp. 5053-5075
Author(s):  
WOLFGANG LUCHA ◽  
FRANZ F. SCHÖBERL
Keyword(s):  
Gauge Coupling ◽  
Coupling Constants ◽  
Coupling Constant ◽  
Finiteness Conditions ◽  
Grand Unified Theories ◽  
Unified Theories ◽  
Dimensionless Coupling ◽  
The One ◽  
The Masses ◽  
Gauge Coupling Constant

By explicit solution of the one-loop finiteness conditions for all dimensionless coupling constants (i.e. the gauge coupling constant as well as Yukawa and quartic scalar-boson self-interaction coupling constants), two classes of grand unified theories characterized by renormalization-group beta functions which all vanish at least at the one-loop level are constructed and analyzed with respect to the (suspected) appearance of quadratic divergences, with the result that without exception in all of these models the masses of both vector and scalar bosons receive quadratically divergent one-loop contributions.

scholarly journals Extended Conformal Symmetry of the One-Dimensional Bose Gas

1997 ◽  
Vol 12 (29) ◽  
pp. 2153-2159 ◽  
Author(s):  
Milena Maule ◽  
Stefano Sciuto
Keyword(s):  
Cartan Subalgebra ◽  
Conformal Symmetry ◽  
Hard Core ◽  
Bose Gas ◽  
Effective Hamiltonian ◽  
Coupling Constant ◽  
Free Fermions ◽  
One Dimensional ◽  
First Order ◽  
The One

We show that the low-lying excitations of the one-dimensional Bose gas are described, at all orders in a 1/N expansion and at the first order in the inverse of the coupling constant, by an effective Hamiltonian written in terms of an extended conformal algebra, namely the Cartan subalgebra of the [Formula: see text] algebra. This enables us to construct the first interaction term which corrects the Hamiltonian of the free fermions equivalent to a hard-core boson system.

scholarly journals THE TYPE OF THE PHASE TRANSITION AND COUPLING VALUES IN λϕ4 MODEL

2012 ◽  
Vol 27 (21) ◽  
pp. 1250116 ◽  
Author(s):  
M. BORDAG ◽  
V. DEMCHIK ◽  
A. GULOV ◽  
V. SKALOZUB
Keyword(s):  
Phase Transition ◽  
Monte Carlo Simulation ◽  
Coupling Constant ◽  
Huge Amount ◽  
Simulation Data ◽  
First Order ◽  
First Order Phase Transition ◽  
Cluster A ◽  
The One ◽  
First Order Phase

The temperature induced phase transition is investigated in the one-component scalar field ϕ4 model on the lattice. Using the GPU cluster a huge amount of Monte Carlo simulation data is collected for a wide interval of coupling values. This gives a possibility to determine the low bound on the coupling constant λ0 when the transition happens and investigate its type. We found that for the values of λ close to this bound a weak-first-order phase transition takes place. It converts into a second-order one with the increase of λ. A comparison with the results obtained in analytic and numeric calculations by other authors is given.

OPTICAL ABSORPTION IN QUANTUM DOTS

2002 ◽  
Vol 16 (10) ◽  
pp. 1489-1497 ◽  
Author(s):  
PHANI MURALI KRISHNA ◽  
SOMA MUKHOPADHYAY ◽  
ASHOK CHATTERJEE
Keyword(s):  
Quantum Dots ◽  
Optical Absorption ◽  
Optical Absorption Coefficient ◽  
Coupling Constant ◽  
Phonon Coupling ◽  
Size Dependent ◽  
Small Quantum ◽  
Electron Phonon Coupling ◽  
The One ◽  
Strong Confinement

The optical absorption behaviour of polar semiconductor quantum dots has been investigated in the strong confinement regime using the adiabatic approximation of Landau and Pekar. It has been shown that optical absorption coefficient becomes strongly size dependent below a certain value of the confinement length and also exhibits interesting crossing behaviour when studied as a function of the electron–phonon coupling constant for different values of the confinement length. It has furthermore been shown that the ratio of the one-phonon part of the oscillator strength to the zero-phonon contribution can be significantly large in a small quantum dot and can also exhibit an interesting minimum structure at certain value of the confinement length for intermediate electron–phonon coupling.

scholarly journals RESONANCE SOLITONS AS BLACK HOLES IN MADELUNG FLUID

2002 ◽  
Vol 17 (24) ◽  
pp. 1601-1619 ◽  
Author(s):  
O. K. PASHAEV ◽  
JYH-HAO LEE
Keyword(s):  
Reaction Diffusion ◽  
Space Time ◽  
Coupling Constant ◽  
De Sitter ◽  
Bilinear Method ◽  
Envelope Solitons ◽  
Gauge Fixing ◽  
Arbitrary Strength ◽  
Madelung Fluid ◽  
The One

Envelope solitons of the Nonlinear Schrödinger equation (NLS) under quantum potential's influence are studied. Corresponding problem is found to be integrable for an arbitrary strength, s ≠ 1, of the quantum potential. For s < 1, the model is equivalent to the usual NLS with rescaled coupling constant, while for s > 1, to the reaction–diffusion system. The last one is related to the anti-de Sitter (AdS) space valued Heisenberg model, realizing a particular gauge fixing condition of the (1+1)-dimensional Jackiw–Teitelboim gravity. For this gravity model, by the Madelung fluid representation we derive the acoustic form of the space–time metric. The space–time points, where dispersion changes the sign, correspond to the event horizon, while the soliton solution to the AdS black hole. Moving with the above bounded velocity, it describes evolution on the one sheet hyperboloid with nontrivial winding number, and creates under collision, the resonance states which we study by the Hirota bilinear method.

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