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2023-08-03
Tuning of resonant doublets in coupled optical cavities
The mode profile of a coupled optical cavity often exhibits a resonant doublet, which arises from the strong coupling between its sub-cavities. Traditional readout methods rely on setting fields of different frequencies to be resonant in either sub-cavity, which is challenging in the case of strong coupling. In this re...
2308.02574v1
2023-08-08
Vibrational coupling to quasi-bound states in the continuum under tailored coupling conditions
Photonic resonance modes can be spectrally coupled to the vibrational modes of molecules in the mid-infrared regime through interactions between localized electric fields and nearby molecules. According to recent studies, radiative loss engineering of coupled systems is a promising approach for tailoring coupling condi...
2308.04630v1
2023-09-11
Topological transitions in dissipatively coupled Su-Schrieffer-Heeger models
Non-Hermitian topological phenomena have gained much interest among physicists in recent years. In this paper, we expound on the physics of dissipatively coupled Su-Schrieffer-Heeger (SSH) lattices, specifically in systems with bosonic and electrical constituents. In the context of electrical circuits, we demonstrate t...
2309.05479v1
2023-09-14
Coupling Constants as Conserved Charges in Black Hole Thermodynamics
In a generic theory of gravity coupled to matter fields, the Smarr formula and the first law of thermodynamics of black holes do not work properly if the contributions of the coupling constants defining the theory are not incorporated. However, these couplings, such as the cosmological constant or the dimensionful para...
2309.07634v1
2023-10-10
Kerr black hole shadows from the axion-photon coupling
We have investigated the motion for photons in the Kerr black hole spacetime under the axion-photon coupling. The birefringence phenomena arising from the axion-photon coupling can be negligible in the weak coupling approximation because the leading-order contributions to the equations of motion come from the square te...
2310.06490v3
2023-10-24
String breaking and running coupling of $\rm Q\bar{Q}$ in a rotating media from holography
Through gravity/gauge duality, the string breaking and running coupling constant of heavy quark-antiquark pair are investigated in the rotating background. For the meson decay mode $\rm Q\bar{Q} \rightarrow Q \bar{q}+\bar{Q} q$, we discuss the string breaking and running coupling in the parallel and transverse case. It...
2310.15609v1
2023-11-07
Non-Hermitian skin effect and nonreciprocity induced by dissipative couplings
We study the mechanism for realizing non-Hermitian skin effect (NHSE) via dissipative couplings, in which the left-right couplings have equal strengths but the phases do not satisfy the complex conjugation. Previous realizations of NHSE typically require unequal left-right couplings or on-site gain and loss. In this wo...
2311.03803v2
2023-12-07
Stiff deployable structures via coupling of thick Miura-ori tubes along creases
Origami-based structures play an important role in the realization of deployable mechanisms and unique mechanical properties via programmable deformation by folding. Among origami-based structures, tessellation by the coupling of origami tubes enriches the variations in geometry and mechanical properties. However, thic...
2312.04048v1
2023-12-27
Topological phase transitions induced by the variation of exchange couplings in graphene
We consider a modified graphene model under exchange couplings. Various quantum anomalous phases are known to emerge under uniform or staggered exchange couplings. We introduce the twist between the orientations of two sublattice exchange couplings, which is useful for examining how such topologically nontrivial phases...
2312.16625v2
2024-01-19
Extremely strong spin-orbit coupling effect in light element altermagnetic materials
Spin-orbit coupling is a key to realize many novel physical effects in condensed matter physics, but the mechanism to achieve strong spin-orbit coupling effect in light element antiferromagnetic compounds has not been explored. In this work, based on symmetry analysis and the first-principles electronic structure calcu...
2401.11065v1
2024-02-14
Sign of the $hZZ$ coupling and implication for new physics
The magnitudes of the couplings of the scalar resonance at 125 GeV with the SM particles are found to be consistent with those of the SM Higgs boson. However, the signs are not experimentally determined in most of the cases, a prime example being that with the $Z$-boson pair. In other words, $\kappa_Z^h$, the ratio of ...
2402.09352v1
2024-04-08
Linear and Nonlinear Coupling of Twin-Resonators with Kerr Nonlinearity
Nonlinear effects in microresonators are efficient building blocks for all-optical computing and telecom systems. With the latest advances in microfabrication, coupled microresonators are used in a rapidly growing number of applications. In this work, we investigate the coupling between twin-resonators in the presence ...
2404.05646v1
1999-04-09
Scaling solutions in general non-minimal coupling theories
A class of generalized non-minimal coupling theories is investigated, in search of scaling attractors able to provide an accelerated expansion at the present time. Solutions are found in the strong coupling regime and when the coupling function and the potential verify a simple relation. In such cases, which include po...
9904120v1
2005-02-19
Quintessence models of Dark Energy with non-minimal coupling
We explore quintessence models of dark energy which exhibit non-minimal coupling between the dark matter and the dark energy components of the cosmic fluid. The kind of coupling chosen is inspired in scalar-tensor theories of gravity. We impose a suitable dynamics of the expansion allowing to derive exact Friedmann-Rob...
0502383v1
2005-09-02
A toy model for coupling accretion disk oscillations to the neutron star spin
Lee, Abramowicz & Kluzniak (2004) demonstrated numerically that rotation of neutron star couples with oscillations of its accretion disk, and excites resonances. No specific coupling was assumed, but magnetic field was suggested as the most likely one. Following this idea, we show (Petri 2005) that if the neutron star ...
0509047v1
1998-01-07
Driven Maps and the Emergence of Ordered Collective Behavior in Globally Coupled Maps
A method to predict the emergence of different kinds of ordered collective behaviors in systems of globally coupled chaotic maps is proposed. The method is based on the analogy between globally coupled maps and a map subjected to an external drive. A vector field which results from this analogy appears to govern the tr...
9801005v1
1993-08-20
Phase separation and pairing in coupled chains and planes
A generalization of the $t-J$ model in a system of two coupled chains or planes is studied by numerical diagonalization of small clusters. In particular, the effect of density fluctuations between these one- or two-dimensional coupled layerson intralayer phase separation and pairing is analyzed. The most robust signals...
9308028v2
1994-10-10
Effective chiral-spin Hamiltonian for odd-numbered coupled Heisenberg chains
An $L \times \infty$ system of odd number of coupled Heisenberg spin chains is studied using a degenerate perturbation theory, where $L$ is the number of coupled chains. An effective chain Hamiltonian is derived explicitly in terms of two spin half degrees of freedom of a closed chain of $L$ sites, valid in the regime ...
9410030v1
1997-03-20
Complex-Temperature Phase Diagrams of 1D Spin Models with Next-Nearest-Neighbor Couplings
We study the dependence of complex-temperature phase diagrams on details of the Hamiltonian, focusing on the effect of non-nearest-neighbor spin-spin couplings. For this purpose, we consider a simple exactly solvable model, the 1D Ising model with nearest-neighbor (NN) and next-to-nearest-neighbor (NNN) couplings. We w...
9703187v1
1998-02-13
Antiferromagnetic interlayer exchange coupling across an amorphous metallic spacer layer
By means of magneto-optical Kerr effect we observe for the first time antiferromagnetic coupling between ferromagnetic layers across an amorphous metallic spacer layer. Biquadratic coupling occurs at the transition from a ferromagnetically to an antiferromagnetically coupled region. Scanning tunneling microscopy images...
9802148v1
1998-04-20
Crossover from Weak- to Strong-Coupling Superconductivity and to Normal State with Pseudogap
For an electron gas with a $ \delta $-function attraction we investigate the crossover from weak-coupling to strong-coupling superconductivity as well as normal state near the temperature $T^*$, at which the strong coupling produces a pseudogap in the energy spectrum due to the binding of electron pairs. We present cur...
9804206v3
1998-10-16
Coupling of intrinsic Josephson oscillations in layered superconductors by charge fluctuations
The coupling of Josephson oscillations in layered superconductors is studied with help of a tunneling Hamiltonian formalism. The general form of the current density across the barriers between the superconducting layers is derived. The induced charge fluctuations on the superconducting layers lead to a coupling of the ...
9810192v1
1998-10-30
The Markov approximation for the atomic output coupler
The regions of validity of the Markov approximation for the coupling of atoms out of an atomic trap are determined. We consider radio-frequency output coupling in the presence of gravity and collisional repulsion, and Raman output coupling. The Markov approximation is crucial in most theoretical descriptions of an atom...
9810413v1
1998-11-02
Transport in Double-Crossed Luttinger Liquids
We study transport through two Luttinger liquids (one-dimensional electrons interacting through a Coulomb repulsion in a metal) coupled together at {\it two} points. External voltage biases are incorporated through boundary conditions. We include density-density couplings as well as single-particle hops at the contacts...
9811011v1
1999-04-15
Frictional Drag Between Coupled 2D Hole Gases in GaAs/AlGaAs Heterostructures
We report on the first measurements of the drag effect between coupled 2D-hole gases. We investigate the coupling by changing the carrier densities in the quantum wells, the widths of the barriers between the gases and the perpendicular magnetic field. From the data we are able to attribute the frictional drag to phono...
9904214v1
1999-05-11
Dynamics of a Ring of Diffusively Coupled Lorenz Oscillators
We study the dynamics of a finite chain of diffusively coupled Lorenz oscillators with periodic boundary conditions. Such rings possess infinitely many fixed states, some of which are observed to be stable. It is shown that there exists a stable fixed state in arbitrarily large rings for a fixed coupling strength. This...
9905140v1
1999-09-18
Universal Scaling of Wave Propagation Failure in Arrays of Coupled Nonlinear Cells
We study the onset of the propagation failure of wave fronts in systems of coupled cells. We introduce a new method to analyze the scaling of the critical external field at which fronts cease to propagate, as a function of intercellular coupling. We find the universal scaling of the field throughout the range of coupli...
9909273v1
2000-02-16
The effect of Hund's Coupling on one-dimensional Luttinger Liquids
Two one-dimensional Luttinger liquid systems coupled by Hund's coupling are studied by the renormalization group and the non-abelian bosonization methods. It is found that the Hund's coupling is always relevant irrespective of the repulsive interaction between electrons within each chain. The properties of the result...
0002231v1
2000-02-18
Many-body CPA for the Holstein-DE model
A many-body coherent potential approximation (CPA) previously developed for the double exchange (DE) model is extended to include coupling to local quantum phonons. The Holstein-DE model studied (equal to the Holstein model for zero Hund coupling) is considered to be a simple model for the colossal magnetoresistance ma...
0002297v1
2000-02-21
New way to achieve chaotic synchronization in spatially extended systems
We study the spatio-temporal behavior of simple coupled map lattices with periodic boundary conditions. The local dynamics is governed by two maps, namely, the sine circle map and the logistic map respectively. It is found that even though the spatial behavior is irregular for the regularly coupled (nearest neighbor co...
0002315v1
2000-03-27
Intertube coupling in ropes of single-wall carbon nanotubes
We investigate the coupling between individual tubes in a rope of single-wall carbon nanotubes using four probe resistance measurements. By introducing defects through the controlled sputtering of the rope we generate a strong non-monotonic temperature dependence of the four terminal resistance. This behavior reflects ...
0003423v1
2000-11-02
Coherent coupling of two quantum dots embedded in an Aharonov-Bohm ring
We define two laterally gated small quantum dots (~ 15 electrons) in an Aharonov-Bohm geometry in which the coupling between the two dots can be broadly changed. For weakly coupled quantum dots we find Aharonov-Bohm oscillations. In an intermediate coupling regime we concentrate on the molecular states of the double do...
0011044v1
2001-06-21
Quantum field effects in coupled atomic and molecular Bose-Einstein condensates
This paper examines the parameter regimes in which coupled atomic and molecular Bose-Einstein condensates do not obey the Gross-Pitaevskii equation. Stochastic field equations for coupled atomic and molecular condensates are derived using the functional positive-P representation. These equations describe the full quant...
0106427v1
2001-12-04
Coupled Growing Networks
We introduce and solve a model which considers two coupled networks growing simultaneously. The dynamics of the networks is governed by the new arrival of network elements (nodes) making preferential attachments to pre-existing nodes in both networks. The model segregates the links in the networks as intra-links, cross...
0112052v2
2002-08-20
Soliton Fermi sea in models of Ising-coupled Kondo impurities
We study a model of Ising-coupled Kondo impurities that can be applied to quantum dots with capacitance coupling, coupled qubits with an incoherent environment, etc. We show that this model becomes equivalent to a Anderson impurity model with a novel solitonic Fermi sea. We derive exact results at the Toulouse point, a...
0208390v2
2002-10-17
Frustration of the interlayer coupling by mobile holes in La2-xSrxCuO4 (x<0.02)
We have studied the interlayer coupling in the antiferromagnetic (AF) phase of Sr and Zn doped La2CuO4 by analyzing the spin flip transition in the magnetization curves. We find that the interlayer coupling strongly depends on the mobility of the hole charge carriers. Samples with the same hole content as well as the s...
0210357v1
2003-04-07
Variable electrostatic transformer: controllable coupling of two charge qubits
We propose and investigate a novel method for the controlled coupling of two Josephson charge qubits by means of a variable electrostatic transformer. The value of the coupling capacitance is given by the discretized curvature of the lowest energy band of a Josephson junction, which can be positive, negative, or zero. ...
0304166v2
2003-08-10
Spectroscopy on two coupled flux qubits
We have performed spectroscopy measurements on two coupled flux qubits. The qubits are coupled inductively, which results in a $\sigma_1^z\sigma_2^z$ interaction. By applying microwave radiation, we observe resonances due to transitions from the ground state to the first two excited states. From the position of these r...
0308192v1
2003-10-01
Rashba coupling in quantum dots: exact solution
We present an analytic solution to the problem of the Rashba spin-orbit coupling in semiconductor quantum dots. We calculate the exact energy spectrum, wave-functions, and spin--flip relaxation times. We discuss various effects inaccessible via perturbation theory. In particular, we find that the effective gyromagnetic...
0310024v2
2004-06-27
Spin transfer and coherence in coupled quantum wells
Spin dynamics of optically excited electrons confined in asymmetric coupled quantum wells are investigated through time resolved Faraday rotation experiments. The inter-well coupling is shown to depend on applied electric field and barrier thickness. We observe three coupling regimes: independent spin precession in iso...
0406668v1
2005-01-11
Nonlinear Coupling in Nb/NbN Superconducting Microwave Resonators
In this experimental study we show that the coupling between Nb/NbN superconducting microwave resonators and their feedline can be made amplitude dependent. We employ this mechanism to tune the resonators into critical coupling condition, a preferable mode of operation for a wide range of applications. Moreover we exam...
0501236v1
2005-01-20
Computing Counterion Densities at Intermediate Coupling
By decomposing the Coulomb interaction into a long distance component appropriate for mean-field theory, and a nonmean-field short distance component, we compute the counterion density near a charged surface for all values of the counterion coupling parameter. A modified strong-coupling expansion that is manifestly fin...
0501498v1
2005-02-14
Interlayer Exchange Coupling in (Ga,Mn)As-based Superlattices
The interlayer coupling between (Ga,Mn)As ferromagnetic layers in all-semiconductor superlattices is studied theoretically within a tight-binding model, which takes into account the crystal, band and magnetic structure of the constituent superlattice components. It is shown that the mechanism originally introduced to d...
0502321v1
2005-02-22
Dynamics of weakly coupled random antiferromagnetic quantum spin chains
We study the low-energy collective excitations and dynamical response functions of weakly coupled random antiferromagnetic spin-1/2 chains. The interchain coupling leads to Neel order at low temperatures. We use the real-space renormalization group technique to tackle the intrachain couplings and treat the interchain c...
0502530v2
2005-03-03
Finite-temperature properties of frustrated classical spins coupled to the lattice
We present extensive Monte Carlo simulations for a classical antiferromagnetic Heisenberg model with both nearest ($J_1$) and next-nearest ($J_2$) exchange couplings on the square lattice coupled to the lattice degrees of freedom. The Ising-like phase transition, that appears for $J_2/J_1>1/2$ in the pure spin model, i...
0503080v1
2005-04-11
Superconducting qubit network with controllable nearest neighbor coupling
We investigate the design and functionality of a network of loop-shaped charge qubits with switchable nearest-neighbor coupling. The qubit coupling is achieved by placing large Josephson junctions at the intersections of the qubit loops and selectively applying bias currents. The network is scalable and makes it possib...
0504250v1
2005-07-29
Charge fluctuation induced dephasing of exchange coupled spin qubits
Exchange coupled {\it spin} qubits in semiconductor nanostructures are shown to be vulnerable to dephasing caused by {\it charge noise} invariably present in the semiconductor environment. This decoherence of exchange gate by environmental charge fluctuations arises from the fundamental Coulombic nature of the Heisenbe...
0507725v2
2005-11-10
Do current-density nonlinearities cut off the glass transition?
Extended mode coupling theories for dense fluids predict that nonlinear current-density couplings cut off the singular `ideal glass transition', present in the standard mode coupling theory where such couplings are ignored. We suggest here that, rather than allowing for activated processes as sometimes supposed, contri...
0511260v1
2005-11-16
Mode-Coupling Theory (MCT) Lecture Notes
In this set of lecture notes we review the mode-coupling theory of the glass transition from several perspectives. First, we derive mode-coupling equations for the description of density fluctuations from microscopic considerations with the use the Mori-Zwanzig projection operator technique. We also derive schematic mo...
0511407v1
2006-02-03
Tunable coupling of qubits: nonadiabatic corrections
We analyze the coupling of qubits mediated by a tunable and fast element beyond the adiabatic approximation. The nonadiabatic corrections are important and even dominant in parts of the relevant parameter range. As an example, we consider the tunable capacitive coupling between two charge qubits mediated by a gated Jos...
0602086v2
2006-04-19
Vibronic solitons in a (nearly-) degenerate electronic system along a 1-D chain
We consider the formation and stability of the vibronic polaron arising in a degenerate or nearly degenerate electronic system coupled to an appropriate vibrational mode. We define the electron-phonon coupling as a mixing of the electronic states by the phonon mode. Our investigation is similar to that carried out rece...
0604462v1
2006-05-28
Generalized switchable coupling for superconducting qubits using double resonance
We propose a method for switchable coupling between superconducting qubits using double resonance. The inter-qubit coupling is achieved by applying near-resonant oscillating fields to the two qubits. The deviation from resonance relaxes the criterion of strong driving fields while still allowing for a fully entangling ...
0605685v2
2006-06-22
Better synchronizability predicted by a new coupling method
In this paper, inspired by the idea that the hub nodes of a highly heterogeneous network are not only the bottlenecks, but also effective controllers in the network synchronizing process, we bring forward an asymmetrical coupling method where the coupling strength of each node depends on its neighbors' degrees. Compare...
0606575v2
2006-12-29
Experimental Observation of Electronic Coupling in GaAs Lateral Quantum Dot Molecules
We report the fabrication and photoluminescence properties of laterally-coupled GaAs/AlGaAs quantum dots. The coupling in the quantum dot molecules is tuned by an external electric field. An intricate behavior, consisting of spectral line crossings and avoided crossings is observed for different molecules. Anticrossing...
0612701v3
2007-01-09
Artificial molecular quantum rings: Spin density functional theory calculations
The ground states of artificial molecules made of two vertically coupled quantum rings are studied within the spin density functional theory for systems containing up to 13 electrons. Quantum tunneling effects on the electronic structure of the coupled rings are analyzed. For small ring radius, our results recover thos...
0701185v1
2006-11-24
Coupling Methodology within the Software Platform Alliances
CEA, ANDRA and EDF are jointly developing the software platform ALLIANCES which aim is to produce a tool for the simulation of nuclear waste storage and disposal repository. This type of simulations deals with highly coupled thermo-hydro-mechanical and chemical (T-H-M-C) processes. A key objective of Alliances is to gi...
0611127v1
1998-07-23
Does the non-minimal coupling of the scalar field improve or destroy inflation ?
The non-minimal coupling of a scalar field to the Ricci curvature in a curved spacetime is unavoidable according to several authors. The coupling constant is not a free parameter: the prescriptions for the value of the coupling constant in specific scalar field and gravity theories (in particular in general relativity)...
9807066v1
2004-09-10
A Nonlinear Coupling Network to Simulate the Development of the r-mode Instablility in Neutron Stars I. Construction
R-modes of a rotating neutron star are unstable because of the emission of gravitational radiation. We explore the saturation amplitudes of these modes determined by nonlinear mode-mode coupling. Modelling the star as incompressible allows the analytic computation of the coupling coefficients. All couplings up to n=30 ...
0409048v1
2006-10-24
Duffin-Kemmer-Petiau equation with nonminimal coupling to curvature
The generalized Duffin-Kemmer-Petiau equation in curved space-time is proposed for non-minimal coupling to the curvature and external fields. The corresponding scalar and vector fields equation are found. Equations are presented, which are equivalent to those of a scalar field with conformal coupling and electromagneti...
0610115v1
2001-02-22
Measurement of the leptoquark Yukawa couplings in e+e- collisions at TESLA
Measurement of the Yukawa couplings of the first-generation leptoquarks has been studied for e+e- collisions at TESLA, at sqrt(s)=800 GeV. By combining measurements from different production and decay channels, determination of Yukawa couplings with precision on the few per-cent level is possible. TESLA will be sensiti...
0102043v1
1995-03-30
Effective Yukawa Couplings in Noncompact Lattice QED
We investigate effective Yukawa couplings of mesons to the elementary fermions in noncompact lattice QED. The couplings are extracted from suitable fermion-antifermion-meson three-point functions calculated by Monte Carlo simulations with dynamical staggered fermions. The scaling behaviour is compatible with expectatio...
9503026v1
2005-10-04
Pionic couplings (g^ and g~) in the static heavy quark limit
The couplings between the soft pion and the doublet of heavy-light mesons are basic parameters of the ChPT approach to the heavy-light systems. We compute the unquenched (Nf=2) values of two such couplings in the static heavy quark limit: (1) g^, coupling to the lowest doublet of heavy-light mesons, and (2) g~, couplin...
0510017v1
1993-06-02
Coupling Constant and Yukawa Coupling Unifications: Uncertainties and Constraints
The status of coupling constant unification (with and without a unification of Yukawa couplings) is discussed. Uncertainties associated with the input coupling constants, $m_{b}$ and $m_{t}$, threshold corrections at the low and high scale, and possible nonrenormalizable operators are described and a discrepancy betwee...
9306213v1
1994-05-02
About the relevance of the Imaginary components of the effective couplings in the Asymmetry measurements
The effect coming from imaginary parts of effective couplings in the $e^+ e^-$ asymmetries is investigated. It is shown that for the present level of experimental accuracy, in some asymmetries the imaginary parts of the effective couplings cannot be neglected and moreover that the use of different prescriptions on how ...
9405201v1
1995-03-06
Threshold Behaviour in Gauge Boson Pair Production at LEP 2
We discuss the form of the amplitude for gauge boson pair production at or near threshold.We show that in the case of W-pair production at LEP2 near threshold only one anomalous electromagnetic coupling can contribute. This anomalous coupling is CP violating and contributes to the electric dipole moment of the $W$. Sin...
9503243v2
1995-06-22
Gauge Coupling Unification in GUT and String Models
The results for the running of the gauge couplings in the MSSM are up-dated by proper inclusion of all low scale effects. They are presented as predictions for the strong coupling constant in the scenario with only two parameters at the GUT scale ~ ($\alpha_{U}$ ~and ~$M_{U}$) ~and as a mismatch of the couplings at the...
9506393v1
1996-10-10
Effects of Anomalous Couplings of Quarks on Prompt Photon Production
Prompt photon production is sensitive to the anomalous couplings of gluons to quarks, because it is mainly produced by quark-gluon scattering. We will examine the effects of the anomalous chromoelectric and chromomagnetic dipole moment couplings of quarks on prompt photon production. Using the data collected by CDF and...
9610318v1
1996-10-29
Suppression of PiNN(1535) Coupling in the QCD Sum Rule
The \pi NN^* and \eta NN^* coupling constants are studied based on the two point functions between the vacuum and a one meson state in the soft meson limit. In terms of a suitably constructed interpolating field for the nucleon and resonances, we have found that the \pi NN^* couplings vanish, while \eta NN^* couplings ...
9610520v2
1997-01-31
Anomalous triple gauge couplings in e+ e- -> W+ W- and "optimal" strategies for their measurement
We show how one can measure anomalous WWZ- and WWgamma-couplings with minimal statistical error using integrated observables, without having to assume that the anomalous couplings are small. We propose a parametrisation of these couplings which is well suited for the extraction of both single and many parameters, and w...
9702208v1
1997-04-03
Reduction of Couplings and Finiteness in Realistic Supersymmetric GUTs
Reduction of couplings in supersymmetric GUTs is achieved by searching for renormalization group invariant (RGI) relations among couplings which hold beyond the unification scale. Finiteness is due to the fact that there exist RGI relations among couplings that guarantee the vanishing of the beta-functions of a N=1 sup...
9704218v1
1997-04-12
Chaotic inflation with running nonminimal coupling
We have found a successful model of chaotic inflation with an inflaton coupled nonminimally with gravity. The nonminimal coupling constant $\xi$ runs with the evolution of the inflaton. The running nature of the coupling leads naturally to the situations where the coupling becomes small enough to have sufficient period...
9704303v2
1997-06-18
Gauge-Boson Pair Production at the LHC: Anomalous Couplings and Vector-Boson Scattering
We compare vector boson fusion and quark antiquark annihilation production of vector boson pairs at the LHC and include the effects of anomalous couplings. Results are given for confidence intervals for anomalous couplings at the LHC assuming that measurements will be in agreement with the standard model. We consider a...
9706406v1
1997-06-24
Some Remarks on the Baryon-Meson Couplings in the 1/N_c Expansion
The original results for the baryon-pion couplings in the large $N_c$ QCD can be understood in a simpler way in the Hartree-Fock picture. The large $N_c$ relation and its $1/N_c$ correction between the heavy baryon-meson coupling and the light baryon-meson coupling are emphasized. Application to the baryon-$\rho$ meson...
9706481v1
1997-07-10
Suppression of PiNN* Coupling and Chiral Symmetry
Meson-baryon couplings between positive and negative parity baryons are investigated using two point correlation functions in the soft meson limit. We find that the pi NN^* coupling vanishes due to chiral symmetry, while the eta NN^* coupling remains finite. We perform an analysis based on the algebraic method for SU(2...
9707307v1
1998-05-19
The Anomalous Magnetic Moment of the Muon and Higgs-Mediated Flavor Changing Neutral Currents
In the two-Higgs doublet extension of the standard model, flavor-changing neutral couplings arise naturally. In the lepton sector, the largest such coupling is expected to be $\mu-\tau-\phi#. We consider the effects of this coupling on the anomalous magnetic moment of the muon. The resulting bound on the coupling, unli...
9805376v1
2000-08-03
Correspondence of consistent and inconsistent spin-3/2 couplings via the equivalence theorem
The Rarita-Schwinger theory of free massive spin-3/2 field obeys the physical degrees of freedom counting, and one can distinguish ``consistent'' couplings which maintain this property and ``inconsistent'' couplings which destroy it. We show how one can obtain consistent couplings from inconsistent ones by a redefiniti...
0008026v2
2002-11-08
Varying Couplings From Orbifold GUTs
We discuss the variation of gauge couplings in time in the framework of orbifold constructions, due to a change of the extra compact dimension's size. Models with gauge coupling unification allow to estimate the variation of the strong coupling constant $\al_3$ and to relate it to a variation of $\alpha_{em}$. The extr...
0211122v2
2003-11-05
$H^+ W^- Z$ contribution to the static quantities of the W boson in the context of Higgs-triplet theories
We calculate the one--loop contribution from the $H^+ W^- Z$ coupling to the static electromagnetic properties of the W boson. Although this coupling is absent at the tree--level in all Higgs--doublet models, it can be induced at this order in models including Higgs--triplet representations. It is found that the $H^+ W...
0311066v1
2004-08-24
Charges and Coupling Strengths in Gauge Theories with Direct Product Symmetry Groups
For gauge theories with direct product internal symmetry groups, the relationship between internal quantum numbers (charges) and coupling strengths is examined. In these types of theories, the Lagrangian density may contain non-trivial factors multiplying the matter field terms, and these factors can modify the interac...
0408266v2
2004-09-28
The Temperature Dependence of the QCD Running Coupling
We study the running of the QCD coupling with the momentum squared ($Q^2$) and the temperature scales in the high temperature limit ($T > T_{c}$), using a mass dependent renormalization scheme to build the Renormalization Group Equations. The approach used guaranty gauge invariance, through the use of the Hard Thermal ...
0409329v1
2006-04-28
New Physics effects in the flavor-changing neutral couplings of the Top quark
We survey the flavor-changing neutral couplings (FCNC) of the top quark predicted by some extensions of the Standard Model: THDM, SUSY, L-R symmetric, TC2, 331, and models with extra quarks. Since the expected sensitivity of the LHC and ILC for the tcV (V=\gamma,g,Z) and tcH couplings is of order of a few percent, we e...
0605003v1
2006-10-23
Light scalars coupled to photons and non-newtonian forces
A particle $\phi$ coupling to two photons couples also to charged particles, like protons, through a loop. If the particle is a light scalar this induced coupling to protons leads to non-newtonian forces. We show that the experimental constraints on exotic, fifth-type forces lead to stringent constraints on the $\phi\g...
0610286v2
1993-04-27
The Strength of String Nonperturbative Effects and Strong-Weak Coupling Duality
A strong-weak coupling duality symmetry of the string equations of motion has been suggested in the literature. This symmetry implies that vacua occur in pairs. Since the coupling constant is a dynamical variable in string theory, tunneling solutions between strong and weak coupling vacua may exist. Such solutions woul...
9304129v2
1995-03-31
Nontrivial, Asymptotically Non-free Gauge Theories and Dynamical Unification of Couplings
An evidence for nontriviality of asymptotically non-free (ANF) Yang-Mills theories is found on the basis of optimized perturbation theory. It is argued that these theories with matter couplings can be made nontrivial by means of the reduction of couplings, leading to the idea of dynamical unification of couplings (DUC)...
9503221v1
1997-01-13
Strong Coupling Expansions of SU(N) Seiberg-Witten Theory
We set up a systematic expansion of the prepotential for ${\cal N}=2$ supersymmetric Yang-Mills theories with SU(N) gauge group in the region of strong coupling where a maximal number of mutually local fields become massless. In particular, we derive the first non-trivial non-perturbative correction, which is the first...
9701055v1
1997-06-04
Exponentially Small Couplings between Twisted Fields of Orbifold String Theories
We investigate the natural occurence of exponentially small couplings in effective field theories deduced from higher dimensional models. We calculate the coupling between twisted fields of the Z_3 Abelian orbifold compactification of the heterotic string. Due to the propagation of massive Kaluza-Klein modes between th...
9706028v1
1998-12-08
Anomalous couplings for D-branes and O-planes
We study anomalous Wess-Zumino couplings of D-branes and O-planes in a general background and derive them from a direct string computation by factorizing in the RR channel various one-loop amplitudes. In particular, we find that Op-planes present gravitational anomalous couplings involving the Hirzebruch polynomial L, ...
9812071v1
2004-09-02
Lagrange Multipliers and Couplings in Supersymmetric Field Theory
In hep-th/0312098 it was argued that by extending the ``$a$-maximization'' of hep-th/0304128 away from fixed points of the renormalization group, one can compute the anomalous dimensions of chiral superfields along the flow, and obtain a better understanding of the irreversibility of RG flow in four dimensional supersy...
0409029v1
2005-04-04
Scalar tensor theory of gravity carrying a conserved current
A general scalar-tensor theory of gravity carries a conserved current for a trace free minimally coupled scalar field, under the condition that the potential $V(\phi)$ of the nonminimally coupled scalar field is proportional to the square of the parameter $f(\phi)$ that is coupled with the scalar curvature $R$. The con...
0504021v1
2007-01-12
Anomalous U(1)'s, Chern-Simons couplings and the Standard Model
This proceeding is based on hep-th/0605225 and it shows that the most general anomaly related effective action contains Stuckelberg, axionic and Chern-Simons-like couplings. Such couplings are generically non-trivial in orientifold string vacua. A similar analysis in quantum field theories provides similar couplings. T...
0701114v2
2002-03-08
Compactification of the moduli spaces of vortices and coupled vortices
Vortices and coupled vortices arise from Yang-Mills-Higgs theories and can be viewed as generalizations or analogues to Yang-Mills connections and, in particular, Hermitian-Yang-Mills connections. We proved an analytic compactification of the moduli spaces of vortices and coupled vortices on hermitian vector bundles ov...
0203078v1
2004-02-23
Coupling Poisson and Jacobi structures on foliated manifolds
Let M be a differentiable manifold endowed with a foliation F. A Poisson structure P on M is F-coupling if the image of the annihilator of TF by the sharp-morphism defined by P is a normal bundle of the foliation F. This notion extends Sternberg's coupling symplectic form of a particle in a Yang-Mills field. In the pre...
0402361v1
2001-01-16
An Exactly Solvable Model for the Interaction of Linear Waves with Korteweg-de Vries Solitons
Under certain mode-matching conditions, small-amplitude waves can be trapped by coupling to solitons of nonlinear fields. We present a model for this phenomenon, consisting of a linear equation coupled to the Korteweg-de Vries equation. The model has one parameter, a coupling constant. For one value of the coupling con...
0101027v1
2002-01-17
Lag time and parameter mismatches in synchronization of unidirectionally coupled chaotic external cavity semiconductor lasers
We report an analysis of synchronization between two unidirectionally coupled chaotic external cavity master/slave semiconductor lasers with two characteristic delay times, where the delay time in the coupling is different from the delay time in the coupled systems themselves. We demonstrate for the first time that par...
0201032v1
2002-08-07
Hierarchy of Chaotic maps with an invariant measure and their coupling
Hierarchy of one-parameter families of chaotic maps with an invariant measure have been introduced, where their appropriate coupling has lead to the generation of some coupled chaotic maps with an invariant measure. It is shown that these chaotic maps (also the coupled maps) do not undergo any period doubling or period...
0208011v1
2005-07-15
Synchronization of coupled chaotic oscillators as a phase transition
We characterize the synchronization of an array of coupled chaotic elements as a phase transition where order parameters related to the joint probability at two sites obey power laws versus the mutual coupling strength; the phase transition corresponds to a change in the exponent of the power law. Since these studies a...
0507030v1
2006-01-31
The Time of Synchronization of Oscillationsin Two Coupled Identical Subsystems
The mechanism of synchronization of oscillations in two identical coupled flow systems has beenstudied. The time (past the coupling onset) during which a synchronous oscillation regime is establisheddepends on the oscillation phase difference between the subsystems. Variation of the coupling parameter leadsto a change ...
0601072v1
2006-03-27
Semi-direct sums of Lie algebras and discrete integrable couplings
A relation between semi-direct sums of Lie algebras and integrable couplings of lattice equations is established, and a practicable way to construct integrable couplings is further proposed. An application of the resulting general theory to the generalized Toda spectral problem yields two classes of integrable coupling...
0603064v1
2006-07-31
Bifurcation and Chaos in Coupled Periodically Forced Non-identical Duffing Oscillators
We study the bifurcations and the chaotic behaviour of a periodically forced double-well Duffing oscillator coupled to a single-well Duffing oscillator. Using the amplitude and the frequency of the driving force as control parameters, we show that our model presents phenomena which were not observed in coupled periodic...
0607074v1
2006-10-10
Isochronal synchrony and bidirectional communication with delay-coupled nonlinear oscillators
We propose a basic mechanism for isochronal synchrony and communication with mutually delay-coupled chaotic systems. We show that two Ikeda ring oscillators (IROs), mutually coupled with a propagation delay, synchronize isochronally when both are symmetrically driven by a third Ikeda oscillator. This synchronous operat...
0610024v1