Effects on the CMB from Compactification Before Inflation

Abstract

Many theories beyond the Standard Model include extra dimensions, though these have yet to be directly observed. In this work we consider the possibility of a compactification mechanism which both allows extra dimensions and is compatible with current observations. This compactification is predicted to leave a signature on the CMB by altering the amplitude of the low l multipoles, dependent on the amount of inflation. Recently discovered CMB anomalies at low multipoles may be evidence for this. In our model we assume the spacetime is the product of a four-dimensional spacetime and flat extra dimensions. Before the compactification, both the four-dimensional space- time and the extra dimensions can either be expanding or contracting independently. Taking into account physical constraints, we explore the observational consequences and the plausibility of these different models.

21 pages, 5 Figures (references added)

References in corpus (5)

• Just enough inflation: power spectrum modifications at large scales
• Observing the Dimensionality of Our Parent Vacuum
• Scalar suppression on large scales in open inflation
• An anisotropic universe due to dimension-changing vacuum decay
• The Initial State of a Primordial Anisotropic Stage of Inflation

Cited by in corpus (5)

• Quantum Corrections and the de Sitter Swampland Conjecture
• Primordial perturbations with pre-inflationary bounce
• The interacting multiverse and its effect on the cosmic microwave background
• Pre-inflation from the multiverse: Can it solve the quadrupole problem in the cosmic microwave background?
• Singularity theorems for warped products and the stability of spatial extra dimensions