On the infrared behaviour of some non-Minkowskian quantum fields
The infrared structure of some quantum fields in several spacetimes was studied. Here infrared refers to effects associated with modes whose wave length is large compared to the characteristic scale of the space. Several situations dealing with aspects of this question are analyzed. It is shown that the infrared behavior of a massless scalar field and an antisymmetric tensor field in de Sitter space are different even though these two fields appear to be formally equivalent. The scalar field does not have a de Sitter-invariant quantum state, while the antisymmetric tensor is shown to have a well-behaved de Sitter-invariant vacuum. The second topic considered is the behavior of the expectation value of phi squared for a massless scalar field phi whose quantum state is free from infrared divergences in spatially flat Robertson-Walker universes. If the universe expands as a power of comoving time and the power is greater than 3/2, then phi squared grows for a finite interval of time. The next topic discussed is zero-frequency modes of massless scalar fields and vector fields in compact spaces. In some spaces they are growing functions of time. It is shown that growth rates can be related to initial conditions of the theory if the mass of the field is a function of time which varies from a constant in the past to 0 in the future. Growth in zero modes of a scalar field phi would lead to growth in phi squared. The relevance of these growing expectation values of squared field operators in global symmetry breaking is studied.
- Research Organization:
- Tufts Univ., Medford, MA (USA)
- OSTI ID:
- 6304199
- Resource Relation:
- Other Information: Ph.D. Thesis
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
SPACE-TIME MODEL
INFRARED SPECTRA
EXPANSION
SCALARS
SYMMETRY BREAKING
TENSORS
THEORETICAL DATA
TIME DEPENDENCE
UNIVERSE
VECTOR FIELDS
CLUSTER EMISSION MODEL
DATA
INFORMATION
MATHEMATICAL MODELS
MULTIPERIPHERAL MODEL
NUMERICAL DATA
PARTICLE MODELS
PERIPHERAL MODELS
SPECTRA
640106* - Astrophysics & Cosmology- Cosmology