Constructing Point Form Mass Operators from Interaction Lagrangians
نویسنده
چکیده
Starting from an interaction Lagrangian formed out of local fields, an interacting four-momentum operator is constructed by integrating the interaction Lagrangian over the forward hyperboloid. Such a four-momentum operator has the property that the components commute among themselves; however, when the Fock space on which the four-momentum operator acts is truncated, the components no longer commute among themselves. By modifying matrix elements of the four-momentum operator on the truncated space, Bakamjian-Thomas mass operators are constructed which restore the Poincare relations. Examples for a simple Lagrangian are given1.
منابع مشابه
Constructing Point Form Mass Operators from Vertex Interactions
A relativistic few-body theory is formulated using point form quantummechanics, in which all of the interactions are in the four-momentum operator and Lorentz transformations are kinematic. The four-momentum operator is written as a product of mass and four-velocity operators, where the mass operator is the sum of free and interacting mass operators. Interacting mass operators are constructed f...
متن کاملFirst Integrals for Two Linearly Coupled Nonlinear Duffing Oscillators
We investigate Noether and partial Noether operators of point type corresponding to a Lagrangian and a partial Lagrangian for a system of two linearly coupled nonlinear Duffing oscillators. Then, the first integrals with respect to Noether and partial Noether operators of point type are obtained explicitly by utilizing Noether and partial Noether theorems for the system under consideration. Mor...
متن کاملTwo-dimensional systems that arise from the Noether classification of Lagrangians on the line
Noether-like operators play an essential role in writing down the first integrals for Euler-Lagrange systems of ordinary differential equations (ODEs). The classification of such operators is carried out with the help of analytic continuation of Lagrangians on the line. We obtain the classification of 5, 6 and 9 Noether-like operators for two-dimensional Lagrangian systems that arise from the s...
متن کاملApplications of Effective Lagrangians
The applications of effective lagrangians to the determination of the effects of physics beyond the Standard Model are briefly described. Emphasis is given to those effective operators which generate the largest deviations form the Standard Model; some applications are described.
متن کاملEquivalent effective Lagrangians for Scherk-Schwarz compactifications
We discuss the general form of the mass terms that can appear in the effective field theories of coordinate-dependent compactifications à la Scherk-Schwarz. As an illustrative example, we consider an interacting five-dimensional theory compactified on the orbifold S/Z2, with a fermion subject to twisted periodicity conditions. We show how the same physics can be described by equivalent effectiv...
متن کامل