44,044 research outputs found
Lagrangian analysis of `trivial' symmetries in models of gravity
We study the differences between Poincare and canonical hamiltonian
symmetries in models of gravity through the corresponding Noether identities
and show that they are equivalent modulo trivial gauge symmetries.Comment: 4 pages, LaTeX; Based on presentation at the conference "Relativity
and Gravitation: 100 Years after Einstein in Prague," held in Prague, June
201
Interpolating Action for Strings and Membranes - a Study of Symmetries in the Constrained Hamiltonian Approach
A master action for bosonic strings and membranes, interpolating between the
Nambu--Goto and Polyakov formalisms, is discussed. The role of the gauge
symmetries vis-\`{a}-vis reparametrization symmetries of the various actions is
analyzed by a constrained Hamiltonian approach. This analysis reveals the
difference between strings and higher branes, which is essentially tied to a
degree of freedom count. The cosmological term for membranes follows naturally
in this scheme. The conncetion of our aproach with the Arnowitt--Deser--Misner
representation in general relativity is illuminated.Comment: LaTex, 23 pages; discussion on ADM representation included and new
references adde
The BFT Method With Chain Structure
We have constructed a modified BFT method that preserves the chain structure
of constraints. This method has two advantages: first, it leads to less number
of primary constraints such that the remaining constraints emerge
automatically; and second, it gives less number of independent gauge
parameters. We have applied the method for bosonized chiral Schwiger model. We
have constructed a gauge invariant embedded Lagrangian for this model.Comment: To appear in Phys. Lett.
Shapes and textures of ferromagnetic liquid droplets
Theoretical calculations, computer simulations and experiments indicate the
possible existence of a ferromagnetic liquid state. Should such a state exist,
demagnetization effects would force a nontrivial magnetization texture governed
by the shape of the liquid droplet. Since liquid droplets are deformable, the
droplet shape couples to the magnetization texture. This paper solves the joint
shape/texture problem subject to the assumption of cylindrical droplet
symmetry. The shape undergoes a change in topology from spherical to toroidal
as exchange energy grows or surface tension decreases.Comment: 7 pages, 2 figures, submitted to Brazilian Journal of Physic
Self dual models and mass generation in planar field theory
We analyse in three space-time dimensions, the connection between abelian
self dual vector doublets and their counterparts containing both an explicit
mass and a topological mass. Their correspondence is established in the
lagrangian formalism using an operator approach as well as a path integral
approach. A canonical hamiltonian analysis is presented, which also shows the
equivalence with the lagrangian formalism. The implications of our results for
bosonisation in three dimensions are discussed.Comment: 15 pages,Revtex, No figures; several changes; revised version to
appear in Physical Review
Universal patterns of inequality
Probability distributions of money, income, and energy consumption per capita
are studied for ensembles of economic agents. The principle of entropy
maximization for partitioning of a limited resource gives exponential
distributions for the investigated variables. A non-equilibrium difference of
money temperatures between different systems generates net fluxes of money and
population. To describe income distribution, a stochastic process with additive
and multiplicative components is introduced. The resultant distribution
interpolates between exponential at the low end and power law at the high end,
in agreement with the empirical data for USA. We show that the increase of
income inequality in USA originates primarily from the increase of the income
fraction going to the upper tail, which now exceeds 20% of the total income.
Analyzing the data from the World Resources Institute, we find that the
distribution of energy consumption per capita around the world can be
approximately described by the exponential function. Comparing the data for
1990, 2000, and 2005, we discuss the effect of globalization on the inequality
of energy consumption.Comment: Accepted to New Journal of Physics. 27 pages (IOP preprint style), 8
figures. V.2: Updated figs. 3 and 8, many references added, all text edited.
V.3: Minor changes, last 3 references added. V.4: Minor stylistic changes and
reference updates in proof
- …