Functional Schroedinger picture of a scalar field in a flat Robertson-Walker spacetime

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:6609183

Samiullah, M

The author studies free and self-interacting quantum field theories of a scalar field in the functional Schroedinger picture. He establishes the renormalizability of the Gaussian wavefunctional approximation to a time-dependent variational principle, both for the Minkowski and the flat Robertson-Walker spacetime. The renormalizability depends upon the specific initial state and reasonable criteria for limiting the initial conditions is discussed. For those initial states that satisfy these criteria, it is shown that the time-dependent variational equations, in the Minkowski spacetime, are made finite by the renormalization prescription used in the vacuum sector. In order to study the dynamics of spacetime in the early universe, he computes a finite and renormalized energy-momentum tensor for both the free and the interacting theory (in the Gaussian approximation) in Robertson-Walker spacetime. Using the adiabatic expansion, he shows that the entire subtraction necessary to make the energy-momentum tensor finite in the free theory can be written in terms of covariantly conserved tensors. He further shows that the same subtraction is sufficient to make the energy-momentum tensor finite in the Gaussian approximation for the interacting theory provided that the mass and the coupling constants are renormalized. As a demonstration of the usefulness of this formalism, the problem of the onset of inflation in the early universe is discussed and a sample numerical computation is presented.

• Research Organization: Boston Univ., MA (USA)
• OSTI ID: 6609183
• Country of Publication: United States
• Language: English

Related Subjects

640106* -- Astrophysics & Cosmology-- Cosmology
645400 -- High Energy Physics-- Field Theory
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
DYNAMICS
EXPANSION
FIELD THEORIES
FUNCTIONS
MECHANICS
NUMERICAL SOLUTION
QUANTUM FIELD THEORY
RENORMALIZATION
SCALAR FIELDS
SCHROEDINGER PICTURE
SPACE-TIME
TENSORS
TIME DEPENDENCE
UNIVERSE
VARIATIONAL METHODS
WAVE FUNCTIONS