scholarly journals ADIABATIC EFFECTIVE ACTION FOR VORTICES IN NEUTRAL AND CHARGED SUPERFLUIDS

1996 ◽  
Vol 10 (15) ◽  
pp. 1875-1894 ◽  
Author(s):  
M. HATSUDA ◽  
M. SATO ◽  
S. YAHIKOZAWA ◽  
T. HATSUDA
Keyword(s):  
Effective Mass ◽  
Vortex Dynamics ◽  
Effective Action ◽  
Vortex Core ◽  
Berry Phase ◽  
Inertial Mass ◽  
The Other ◽  
Zero Temperature ◽  
Magnus Force ◽  
Phase Term

Adiabatic effective action for vortices in neutral and charged superfluids at zero temperature are calculated using the topological Landau-Ginzburg theory recently proposed by Hatsuda, Yahikozawa, Ao and Thouless, and vortex dynamics are examined. The Berry phase term arising in the effective action naturally yields the Magnus force in both neutral and charged superfluids. It is shown that in neutral superfluid there is only one degree of freedom, namely the center of vorticities, and the vortex energy is proportional to the sum of all vorticities so that it is finite only for the vanishing total vorticity of the system. On the other hand the effective mass and the vortex energy for a vortex in charged superfluids are defined individually as expected. The effects of the vortex core on these quantities are also estimated. The possible depinning scenario which is governed by the Magnus force and the inertial mass is also discussed.

scholarly journals More on complex Sachdev-Ye-Kitaev eternal wormholes

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Pengfei Zhang
Keyword(s):  
Black Hole ◽  
Ground State ◽  
Effective Action ◽  
Chemical Potential ◽  
Specific Charge ◽  
Zero Temperature ◽  
Small Coupling ◽  
Chemical Potentials ◽  
Quench Dynamics ◽  
Two Sides

Abstract In this work, we study a generalization of the coupled Sachdev-Ye-Kitaev (SYK) model with U(1) charge conservations. The model contains two copies of the complex SYK model at different chemical potentials, coupled by a direct hopping term. In the zero-temperature and small coupling limit with small averaged chemical potential, the ground state is an eternal wormhole connecting two sides, with a specific charge Q = 0, which is equivalent to a thermofield double state. We derive the conformal Green’s functions and determine corresponding IR parameters. At higher chemical potential, the system transit into the black hole phase. We further derive the Schwarzian effective action and study its quench dynamics. Finally, we compare numerical results with the analytical predictions.

Intervalley kinetic energy terms in the effective mass equation: a one-dimensional analytical study

1989 ◽  
Vol 67 (9) ◽  
pp. 896-903 ◽  
Author(s):  
Lorenzo Resca
Keyword(s):  
Kinetic Energy ◽  
Effective Mass ◽  
Analytical Study ◽  
Three Dimensional ◽  
Real Space ◽  
The Other ◽  
Alternative Formulation ◽  
One Dimensional ◽  
Symmetry Properties ◽  
Band Case

We show that a one-dimensional analytical study allows us to test and clarify the derivation, assumptions, and symmetry properties of the intervalley effective mass equation (IVEME). In particular, we show that the IVEME is consistent with a two-band case, and is in fact exact for a model that satisfies exactly all its assumptions. On the other hand, an alternative formulation in k-space that includes intervalley kinetic energy terms is consistent with a one-band case, provided that intra-valley kinetic energy terms are also calculated consistent with one band. We also show that the standard symmetry assumptions for both real space and k-space formulations are not actually exact, but are consistent with a "total symmetric" projection, or with taking spherical averages in a three-dimensional case.

scholarly journals PERSISTENCE IN THE ZERO-TEMPERATURE DYNAMICS OF THE Q-STATES POTTS MODEL ON UNDIRECTED-DIRECTED BARABÁSI–ALBERT NETWORKS AND ERDÖS–RÉNYI RANDOM GRAPHS

2008 ◽  
Vol 19 (12) ◽  
pp. 1777-1785 ◽  
Author(s):  
F. P. FERNANDES ◽  
F. W. S. LIMA
Keyword(s):  
Random Graphs ◽  
Potts Model ◽  
Finite Size ◽  
Glauber Dynamics ◽  
The Other ◽  
Finite Size Effect ◽  
Zero Temperature ◽  
Temperature Dynamics ◽  
Short Times ◽  
Q Values

The zero-temperature Glauber dynamics is used to investigate the persistence probability P(t) in the Potts model with Q = 3, 4, 5, 7, 9, 12, 24, 64, 128, 256, 512, 1024, 4096, 16 384, …, 230 states on directed and undirected Barabási–Albert networks and Erdös–Rényi (ER) random graphs. In this model, it is found that P(t) decays exponentially to zero in short times for directed and undirected ER random graphs. For directed and undirected BA networks, in contrast it decays exponentially to a constant value for long times, i.e., P(∞) is different from zero for all Q values (here studied) from Q = 3, 4, 5, …, 230; this shows "blocking" for all these Q values. Except that for Q = 230 in the undirected case P(t) tends exponentially to zero; this could be just a finite-size effect since in the other "blocking" cases you may have only a few unchanged spins.

scholarly journals Form factor decompositions of the QCD four - gluon vertex

2018 ◽  
Vol 182 ◽  
pp. 02114 ◽  
Author(s):  
Naser Ahmadiniaz ◽  
Christian Schubert
Keyword(s):  
Field Theory ◽  
Form Factor ◽  
Effective Action ◽  
The Other ◽  
Integration By Parts ◽  
Ward Identities ◽  
Gauge Invariant ◽  
Gluon Vertex ◽  
Invariant Structures ◽  
String Amplitudes

The Bern-Kosower formalism, originally developed around 1990 as a novel way of obtaining on-shell amplitudes in field theory as limits of string amplitudes, has recently been shown to be extremely effcient as a tool for obtaining form factor decompositions of the N - gluon vertices. Its main advantages are that gauge invariant structures can be generated by certain systematic integration-by-parts procedures, making unnecessary the usual tedious analysis of the non-abelian off-shell Ward identities, and that the scalar, spinor and gluon loop cases can be treated in a unified way. After discussing the method in general for the N - gluon case, I will show in detail how to rederive the Ball- Chiu decomposition of the three - gluon vertex, and finally present two slightly different decompositions of the four - gluon vertex, one generalizing the Ball Chiu one, the other one closely linked to the QCD effective action.

Differential Boundary-Layer Separation Effects in the Flow over a Rotating Cylinder

1969 ◽  
Vol 73 (702) ◽  
pp. 524-528 ◽  
Author(s):  
R. T. Griffiths ◽  
C. Y. Ma
Keyword(s):  
Boundary Layer ◽  
Flow Velocity ◽  
Lift Force ◽  
Boundary Layer Separation ◽  
Rotating Cylinder ◽  
The Other ◽  
Viscous Drag ◽  
Magnus Force ◽  
Rotating Body ◽  
Rotating Surface

When a rotating body is placed in a stream of fluid the viscous drag of the rotating surface moving forward on one side and backwards on the other causes the flow velocity to be lower and hence the pressure on the forward-moving side higher than on the backward-moving side, thus giving a lateral (lift) force L in the direction shown in Fig. 1. This force, known as the Magnus force, is well known to engineers and also to sportsmen. In tennis, for example, top spin is used to swerve a fast ball downwards so that it falls within the required area of play, while in golf the Magnus force causes the all too familiar sliced shot when the club is drawn across the ball at impact.

Vortex dynamics in superfluids and the Berry phase

1993 ◽  
Vol 200 (1-4) ◽  
pp. 42-49 ◽  
Author(s):  
D.J. Thouless ◽  
P. Ao ◽  
Q. Niu
Keyword(s):  
Vortex Dynamics ◽  
Berry Phase

Berry phase from vortex dynamics in BCS superconductors revisited

1999 ◽  
Vol 313 (1-2) ◽  
pp. 141-147 ◽  
Author(s):  
Akihiro Tanaka ◽  
Masahiko Machida
Keyword(s):  
Vortex Dynamics ◽  
Berry Phase ◽  
Bcs Superconductors

Urbanization and the Interpretation of Misfortune: A Quantitative Analysis

Africa ◽  
1970 ◽  
Vol 40 (1) ◽  
pp. 25-39 ◽  
Author(s):  
W. D. Hammond-Tooke
Keyword(s):  
Quantitative Analysis ◽  
Effective Action ◽  
Urban Areas ◽  
Quantitative Methods ◽  
Social Economic ◽  
Urban Community ◽  
The Other ◽  
Human Relationships ◽  
Western Influence ◽  
Opening Paragraph

Opening ParagraphThe general aim of this paper is to test by quantitative methods Mitchell's statement (Mitchell, 1965, p. 193) that ‘we expect the meaning which people read into misfortunes to change when they become part of an industrial urban community’. Mitchell was commenting (and elaborating) on the demonstration by Marwick (1952) that witchcraft accusations are particularly likely to occur between people who are in competition with one another, but who are prevented by the norms of the society from expressing their hostility openly. He suggests that Africans in town continue to interpret their misfortunes in ‘personal’ terms but that ‘the meaning that they attach to the misfortune must be of a type which will allow them to take effective action’. In the towns of the Copperbelt hostility and opposition may be openly expressed toward strangers, so there is no need for accusations of witchcraft (signalling interpersonal tensions), except where townsfolk are linked in co-operative enterprises in which, nevertheless, there is an element of competition, e.g. as between rival beerbrewers or fellow workers. In such cases open accusation tends to be inhibited and the interpretation recouched in terms of ancestral wrath. Mitchell sees, therefore, an increase in ancestor-centred explanation of misfortune in urban areas and implies a decrease in witch accusations. Marwick has suggested, on the other hand, that ‘the immediate effect of contact with Western influence is not a decrease but an increase in the African's preoccupation with magic, witchcraft and sorcery’, due to new social alignments and social, economic and political changes, which create insecurity, anxiety, and impart a ‘dangerous flexibility’ to human relationships (Marwick, 1958, p. 106).

NÖTHER’S SYMMETRIES IN (n+1)-DIMENSIONAL NONMINIMALLY COUPLED COSMOLOGIES

1993 ◽  
Vol 02 (04) ◽  
pp. 463-476 ◽  
Author(s):  
SALVATORE CAPOZZIELLO ◽  
RUGGIERO DE RITIS ◽  
PAOLO SCUDELLARO
Keyword(s):  
Scalar Field ◽  
General Solution ◽  
Effective Action ◽  
The Other ◽  
Spatial Curvature ◽  
General Transformation ◽  
Systematic Analysis ◽  
Induced Gravity ◽  
Constant Of Motion ◽  
Spatial Dimensions

We perform a systematic analysis of nonminimally coupled cosmologies in (n+1)-dimensional homogeneous and isotropic spacetimes, searching for Nöther’s symmetries and generalizing the results of our previous works. We obtain (i) the absence of symmetries when the spatial curvature constant k is nonzero and n=2, 3, but their existence for all the other n; (ii) the existence of such symmetries for every number of spatial dimensions (except n=1) when k=0. In this latter case, we are able to find a general transformation through which we recover the string-dilaton effective action in (n+1) dimensions and the major peculiarity of string cosmology: the scale factor duality. Furthermore, the symmetry fixes a relation among the coupling F(ϕ), the potential V(ϕ) of the scalar field ϕ, the number of spatial dimensions and the spatial curvature constant. When this is the case, it is possible to find a constant of motion and then get the general solution of the dynamics. Finally, in the framework of the so-called Induced Gravity Theories, we are able to obtain the Newton constant at the present time (t→∞) depending on the number of spatial dimensions and directly related to the constant of motion existing in such a model.

scholarly journals On the expediency of assigning specific names to such functions of simple elements as represent definite physical properties; with the suggestion of a new term in mechanics; illustrated by an investigation of the machine moved by recoil, and also by some observations on the steam engine

1833 ◽  
Vol 2 ◽  
pp. 299-300
Keyword(s):  
Physical Properties ◽  
Effective Action ◽  
The Other ◽  
Steam Engine ◽  
Similar Function ◽  
Centre Of Gravity ◽  
Elastic Bodies ◽  
General Law ◽  
The Subject ◽  
The Common

The author commences this paper by stating the necessity of distinguishing by separate appellations all such functions as measure the intensity of physical properties, which he considers rendered obvious by a reference to the controversy respecting motion. The subject of this controversy, he observes, was the measure of motion itself, it being contended on one hand that the motion of a body is always proportional to its weight multiplied by its velocity; this opinion being supported by reference to the properties of the common centre of gravity of systems, &c.; while on the other hand the affections of elastic bodies in collision, and the general law of the conservation of living or active forces, were adduced in support of the latter measure. No sooner, however, were the terms “momentum” and “impetus” introduced into the science of mechanics, than the opinions of the contending parties were reconciled by the removal of every ground of dispute. In the Bakerian lecture on the force of percussion, read to this Society in 1806, he observes, it is remarked, that neither impetus nor momentum are usually correct measures of the effective action of machines. The criterion of this is the force exerted, multiplied by the space through which it acts, and this measure numerically expressed has been denominated duty by Mr. Watt; and the raising of one pound one foot high has been by him made the dynamic unit; according to which estimate, the duty performed by one bushel of coals, of 84 pounds, has been found to vary from 30 to 50 millions of such units, according to the nature of the engine, and the mode of combustion. To the measure or function represented by the force applied, multiplied by the space through which it acts, the author, however, proposes to give the name efficiency, retaining the word duty for a similar function, indicative of the work performed; and by a comparison of these two functions, viz. the efficiency expended on, and the duty performed by, any machine, an exact measure of its intrinsic work will be obtained.

Sign in / Sign up

Export Citation Format

Share Document