Imperial College London

Carlo R. Contaldi

Faculty of Natural SciencesDepartment of Physics

Professor of Theoretical Physics



+44 (0)20 7594 1527c.contaldi




505Huxley BuildingSouth Kensington Campus






BibTex format

author = {Contaldi, CR and Magueijo, J},
doi = {10.1103/PhysRevD.98.043523},
journal = {Physical Review D},
title = {Unsqueezing of standing waves due to inflationary domain structure},
url = {},
volume = {98},
year = {2018}

RIS format (EndNote, RefMan)

AB - The so-called trans-Planckian problem of inflation may be evaded by positing that modes come into existence only when they became “cis-Planckian” by virtue of expansion. However, this would imply that for any mode a new random realization would have to be drawn every N wavelengths, with N typically of order 1000 (but it could be larger or smaller). Such a redrawing of realizations leads to a heteroskodastic distribution if the region under observation contains several such independent domains. This has no effect on the sampled power spectrum for a scale-invariant raw spectrum, but at very small scales, it leads to a spectral index bias toward scale invariance and smooths oscillations in the spectrum. The domain structure would also “unsqueeze” some of the propagating waves, i.e., dismantle their standing wave character. By describing standing waves as traveling waves of the same amplitude moving in opposite directions, we determine the observational effects of unsqueezing. We find that it would erase the Doppler peaks in the cosmic microwave background, but only on very small angular scales, in which the primordial signal may not be readily accessible. The standing waves in a primordial gravitational wave background would also be turned into traveling waves. This unsqueezing of the gravitational wave background may constitute a detectable phenomenon.
AU - Contaldi,CR
AU - Magueijo,J
DO - 10.1103/PhysRevD.98.043523
PY - 2018///
SN - 2470-0010
TI - Unsqueezing of standing waves due to inflationary domain structure
T2 - Physical Review D
UR -
UR -
UR -
VL - 98
ER -