3 papers
astro-ph2002
Primordial perturbations from inflation
David Wands
I review the standard analysis of adiabatic scalar and tensor perturbations produced by slow-roll inflation driven by a single scalar field, before going on to discuss recent work…
gr-qc1998
Gauge-Invariant Variables on Cosmological Hypersurfaces
Karim A. Malik, David Wands
We show how gauge-invariant cosmological perturbations may be constructed by an unambiguous choice of hypersurface-orthogonal time-like vector field (i.e., time-slicing). This may…
astro-ph1996
Density Perturbations from Two-field Inflation
David Wands, Juan Garcia-Bellido
We discuss metric perturbations produced during a period of inflation in the early universe where two scalar fields evolve. The final scalar perturbation spectrum can be calculated…