Spacetimes with killing tensors

For Einstein-Maxwell fields for which the Weyl spinor is of type {2, 2}, and the electromagnetic field spinor is of type {1, 1} with its principal null directions coaligned with those of the Weyl spinor, the integrability conditions for the existence of a certain valence two Killing tensor are shown to reduce to a simple criterion involving the ratio of the amplitude of the Weyl spinor to the amplitude of a certain test solution of the spin two zero restmass field equations. The charged Kerr solution provides an example of a spacetime for which the criterion is satisfied; the chargedC-metric provides an example for which it is not.This piece of work was completed, in part, during the authors' summer 1972 stays at The University of Texas at Dallas, Division of Mathematics and Mathematical Physics, the Max-Planck-Institut für Physik und Astrophysik in München, and the Black Hole session of the Ecole d'été de Physique Théorique in Les Houches; supported, in part, by the National Science Foundation, Grants GP-8868, GP-3463 9X, GP-20023, and GU-1598; the Air Force Office of Scientific Research, Grant 903-67; the National Aeronautics and Space Administration, Grant 44-004-001; the Westinghouse Corporation; the Clark Foundation; and the Rhodes Trust.     

A generalized Reissner-Nordström solution

A new class of solutions to the Einstein-Maxwell equations is presented; it stands in the same relation to the Robinson & Robinson (1969) metrics as the Reissner-Nordström solution to Schwarzschild's.This work was supported in part by the Aerospace Research Laboratories, Office of Aerospace Research, United States Air Force, under Contract F33615-68-C-1675; Air Force Office of Scientific Research, Office of Aerospace Research, United States Air Force, under AFOSR Grant No. 903-67; National Aeronautics and Space Administration under NASA Grant No. NGL 44-004-001; and National Science Foundation under Travel Grant GP-14505.     

Generalized Vaidya metrics

We investigate criteria under which one may construct the energy tensor of a null radiation field from an algebraically special vacuum metric. The field bears the same relationship to the original metric as does Vaidya's to Schwarzschild's. As an example we generate a class of null radiation fields from a class of vacuum metrics without symmetry discovered by Robinson and Robinson.Supported in part by the National Science Foundation (GP-8868, GP-20033, and GU-1598), Air Force Office of Scientific Research under Grant AF-AFOSR-903-67 and by the National Aeronautics and Space Administration under NASA Grant No. NGL 44-004-001.     

Distributional limits of renormalized Feynman integrals with zero-mass denominators

It is shown that the 0 limits of renormalized Feynman integrals exist and define Lorentz invariant tempered distributions in the external momenta. The proof applies to the case where some or all particle masses vanish.Research supported in part by the National Science Foundation Grant MPS-74-21778.Research supported in part by the National Science Foundation Grant GP-43758.     

On a quadratic first integral for the charged particle orbits in the charged Kerr solution

Associated with the charged Kerr solution of the Einstein gravitational field equation there is a Killing tensor of valence two. The Killing tensor, which is related to the angular momentum of the field source, is shown to yield a quadratic first integral of the equation of the motion for charged test particles.The research reported herein has been supported in part by the National Science Foundation, grants GP-8868, GP-20023, and GU-1598; the Air Force Office of Scientific Research, grant 903-67; the National Aeronautics and Space Administration, grant 44-004-001; and the Westinghouse Corporation.     

Relation between classical and quantum mechanics

Expressions for the Lie derivatives of functions of non-commuting variables are derived and used to reformulate classical mechanics. This is possible only if the phase space variables commute, or if they satisfy Heisenberg's commutation relations.This work was supported in part by the National Science Foundation Grant Number NSF GP-14803, and by the Air Force Office of Scientific Research, contract number AFOSR 68-1524.     

Shear-free,twisting Einstein-Maxwell metrics in the Newman-Penrose formalism

The problem of finding algebraically special solutions of the vacuum Einstein-Maxwell equations is investigated using the spin coefficient formalism of Newman and Penrose. The general case, in which the degenerate null vectors are not hypersurface orthogonal, is reduced to a problem of solving five coupled differential equations that are no longer dependent on the affine parameter along the degenerate null directions. It is shown that the most general regular, shearfree, nonradiating solution of these equations is the Kerr-Newman metric.Based in part on a doctoral thesis submitted to the University of Pittsburgh (1970) while the author was NASA Predoctoral Trainee. Research also supported in part by the National Science Foundation under Grant GP-19378.     

Geometry in a manifold with projective structure

Parallel transport of line elements, surface elements etc. along geodesics and more general curves in a projectively connected manifold is investigated analytically and in terms of geometrical constructions. Projective curvature is characterized geometrically by a projective analogue of the geodesic deviation equation and by a geometrical construction. The results are interpreted physically as statements about free fall world lines in space-time.This paper is dedicated to our friend John Archibald Wheeler, geometer and physicist, who celebrated his sixtieth birthday on July 9, 1971.This work was supported in part by the National Science Foundation (Grant No. GP-34639X). One of the authors (A.S.) did much of this work while visiting the Université Libre de Bruxelles (summer, 1968), Cambridge University (summer, 1970), and the Nordic Institute for Theoretical Atomic Physics (1970-71); he wishes to thank these institutions and Drs. I. Prigogine, D. Sciama, and C. Møller for their kind hospitality.     

Phase space cell expansion and borel summability for the Euclidean φ 3 4 theory

The stability of the free energy is proved for complex values of the coupling constant by the way of a convergent expansion. As a consequence, one obtains the Borel summability of the perturbation series.On leave of absence from the Centre de Physique Théorique, Ecole Polytechnique, Palaiseau, FranceSupported in part by the National Science Foundation under Grant PHY 75-21212     

The monodromy rings of one loop Feynman integrals

The monodromy rings of Feynman integrals for one loop graphs with an arbitrary number of lines are determined.Research sponsored by the National Science Foundation, Grant No. GP-16147.     

A note on reflection positivity

We establish reflection positivity of covariance operators, using properties of Dirichlet or Neumann boundary data.Supported in part by National Science Foundation Grant No. PHY 78-08066.Supported in part by National Science Foundation Grant No. PHY 77-18762.     

On the theory of Brownian motion. II. Nonuniform systems

An equation of evolution for a heavy particle immersed in a solvent of lighter particles is derived for the case when the system suffers gradients of temperature composition, or velocity. The derivation unifies the theory by applying the same methods which have proved useful in the uniform case. The final equation contains some new terms due to concentration gradients in the solvent, and is applicable to the case when the heavy particles are present at finite concentration and interact with each other.This work, part of research supported by NSF Grant GP-8497, was done under the tenure of a National Science Foundation Senior Postdoctoral Fellowship and a sabbatical leave from the University of Oregon.     

Existence of conserved currents in the perturbative sine-Gordon and massive thirring models

The existence of infinitely many conserved currents in the quantized sine-Gordon and massive Thirring models is proved in renormalized perturbation theory.Research supported in part by National Science Foundation Grant No. PHY 74-22218 A03Research supported in part by National Science Foundation Grant No. MP 574-05783 A01     

On the statistics of a three-dimensional gas of long thin rods

A gas of long thin rods undergoes an order-disorder phase transition as a function of rod concentration. We have evaluated the critical concentration at which this first-order transition occurs using Onsager's hard-core interaction model. We obtain the nematic angular distribution function of rods in the ordered phase expanded in a series of Legendre polynomials.This work was partially supported by the National Science Foundation through Grant No. GP-10536.     

On the theory of Brownian motion. I. Interaction between Brownian particles

The molecular theory of the Brownian motion of heavy particles in a homogeneous solvent of light particles is extended to cover the case of interactions between the Brownian particles. This will have physical effects in the concentration dependence of the Brownian particle self-diffusion coefficient. A density expansion for the Brownian particle friction coefficient is derived, and an approximation permitting the first density correction to be calculated is suggested.This work, part of research supported by NSF Grant GP-8497, was done under the tenure of a National Science Foundation Senior Postdoctoral Fellowship, and of a sabbatical leave granted by the University of Oregon.     

Operator product expansions and composite field operators in the general framework of quantum field theory

The short distance behavior of field operator products is analyzed. It is shown that under certain conditions operator product expansions can be derived which give complete information on the short distance behavior and lead to the construction of composite field operators.Suported in parts by funds from the National Science Foundation Grant No. GP-25609.     

Tensors,spinors, and functions on the unit sphere

A representation of tensors and spinors at a point of space-time as spin and conformally weighted functions on the unit sphere is derived. Methods for performing algebraic operations on tensors and spinors in this representation are discussed.Supported in part by grants Nos. GP-35773X1 and MPS74-18020 from the National Science Foundation.     

Entropy inequalities

Some inequalities and relations among entropies of reduced quantum mechanical density matrices are discussed and proved. While these are not as strong as those available for classical systems they are nonetheless powerful enough to establish the existence of the limiting mean entropy for translationally invariant states of quantum continuous systems.Work supported by National Science Foundation Grant GP-9414.     

Gross-Neveu model through convergent perturbation expansions

We construct a continuum limit for the effective low energy Lagrangians of the Gross-Neveu model in two euclidean dimensions by showing that they are related to each other through convergent perturbation expansions. This provides a rigorous control of the ultraviolet problem in a renormalizable quantum field theory.Supported in part by the National Science Foundation under Grant MCS-81-20833Supported in part by the National Science Foundation under Grant PHY-82-03669     

Ergodic properties of an infinite system of particles moving independently in a periodic field

We investigate the ergodic properties of a general class of infinite systems of independent particles which undergo nontrivial collisions with an external field, e.g. fixed convex barriers (the Lorentz gas). We relate the ergodic properties of these systems to the ergodic properties for a single particle moving in a finite box (with periodic boundary conditions) with the same dynamics. We prove that when the one particle system is mixing or aK-system for a sequence of boxes approaching infinity so is the infinite particle system with an equilibrium measure obtained as a Poisson construction over the one particle phase space.Research sponsored in part by the Air Force Office of Scientific Research Grant No. 73-2430 A and The National Science Foundation Grant No. GP-16147 A, No. 1.