Inflation power spectrum
Web30 mrt. 2024 · We consider an analogue de Sitter cosmos in an expanding quasi-two-dimensional Bose-Einstein condensate with dominant dipole-dipole interactions between the atoms or molecules in the ultracold gas. It is demonstrated that a hallmark signature of inflationary cosmology, the scale invariance of the power spectrum of inflaton field … WebThe power of x p(n)is given by P xp = 1/2 −1/2 S xpxp(f)df =r xpxp(0) (6) Example 3.1 Determine the autocorrelation function and power spectrum of the tone signal: x p(n)=acos(2πf xn+θ) with frequency 0 ≤ f x ≤ 1/2.The necessary requirement for x p(n)to be periodic is that the fundamental integer period Nis chosen according to Nf x =qwhere qis …
Inflation power spectrum
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Web11 apr. 2024 · For k < 10 Mpc − 1, the spectrum is flat and the amplitude fits with the CMB observational data. For 10 Mpc − 1 < k < 10 3 Mpc − 1, the power spectrum increases with k and reaches a peak at around k ∼ 10 3 Mpc − 1. For k > 10 3 Mpc − 1 where the fluctuation modes go deep into the subhorizon, the spectrum exhibits oscillating behavior. Web30 aug. 2016 · The power spectrum is a general term that describes the distribution of power contained in a signal as a function of frequency. From this perspective, we can have a power spectrum that is defined over a discrete set of frequencies (applicable for infinite length periodic signals) or we can have a power spectrum that is defined as a …
WebThe power spectrum of the cosmic microwave background from both the Planck and WMAP data exhibits a slight dip for multipoles in the range of l=10−30. We show that such a dip could be the result of the resonant creation of massive particles that couple to the inflaton field. For our best-fit models, the epoch of resonant particle creation reenters the …
Web27 nov. 2024 · In order to generate them, the power spectrum needs to grow many orders of magnitude larger than its observed value on CMB scales - typically achieved through a phase of ultra slow-roll inflation - and is thus subject to … Web10 apr. 2024 · It is also found that although in the course of the Universe inflation and in the models of interest, the backreaction of 〈 φ 2 〉 does not play a significant role in the evolution of the background fields. Instead, they indeed give visible effects in the mode functions ζ k for relatively small k modes, which will affect the power spectrum of the …
Web4 apr. 2024 · Within canonical single field inflation models, we provide a method to reverse engineer and reconstruct the inflaton potential from a given power spectrum. This is not only a useful tool to find a… Expand 80 Highly Influential PDF View 4 excerpts, references background and methods On primordial black holes from an inflection point
Web1 jun. 2024 · As in the result for the canonical inflation, the regularized power spectrum tends to the "bare" power spectrum as the Universe expands during (and even after) inflation. This work justifies the use of the "bare" power spectrum in standard calculation in the most general context of slow-roll single-field inflation involving nonminimal coupling … floral beamWeb7 nov. 2012 · The effects on the power spectrum are studied within the context of universality classes for small-field models. These effects are shown to scale with … great sandy straitsThe scalar spectral index describes how the density fluctuations vary with scale. As the size of these fluctuations depends upon the inflaton's motion when these quantum fluctuations are becoming super-horizon sized, different inflationary potentials predict different spectral indices. Meer weergeven Primordial fluctuations are density variations in the early universe which are considered the seeds of all structure in the universe. Currently, the most widely accepted explanation for their origin is in the context of Meer weergeven Adiabatic fluctuations are density variations in all forms of matter and energy which have equal fractional over/under densities in the number density. So for example, an adiabatic Meer weergeven • Crotty, Patrick, "Bounds on isocurvature perturbations from CMB and LSS data". Physical Review Letters. arXiv:astro-ph/0306286 Meer weergeven Primordial fluctuations are typically quantified by a power spectrum which gives the power of the variations as a function of spatial scale. Within this formalism, one usually considers the fractional energy density of the fluctuations, given by: Meer weergeven • Physics portal • Big Bang • Cosmological perturbation theory Meer weergeven floral beauty shipperWeb1 sep. 2009 · The U.S. Department of Energy's Office of Scientific and Technical Information Signature of short distance physics on inflation power spectrum and CMB anisotropy (Journal Article) OSTI.GOV skip to main content great sandy straits mapWebThe primordial power spectrum Summarizing the results of the last section, inflation predicts not only a flat, smooth universe, but also provides a natural mechanism for the … great sandy straits breakfreeWeb1 sep. 2024 · In the cases we discuss, the enhancement in the power spectrum results from either a swift change in some effective coupling or a modification of the dispersion … floral beadwork on leather backingWeb1 jun. 2024 · The latest CMB limits the spectral index of the power spectrum to be \(n_s=0.9649\pm 0.0042\) at the \(68\%\) confidence level (CL) . ... we investigate the production of GWs during preheating in the Starobinsky inflation model. The energy density and spectrum of GWs will be analyzed detailedly by using the lattice simulation. floral beauty shot