Articles with "power spectrum" as a keyword



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Large power spectrum and primordial black holes in the effective theory of inflation

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Published in 2022 at "Journal of High Energy Physics"

DOI: 10.1007/jhep01(2022)074

Abstract: We study the generation of a large power spectrum, necessary for primordial black hole formation, within the effective theory of single-field inflation. The mechanisms we consider include a transition into a ghost-inflation-like phase and scenarios… read more here.

Keywords: large power; power spectrum; inflation; power ... See more keywords
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Wavelet power spectrum and cross-coherency of Spanish economic variables

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Published in 2018 at "Empirical Economics"

DOI: 10.1007/s00181-017-1295-5

Abstract: We analyze six relevant economic and financial variables for the period 2000M1–2015M3 in the context of the Spanish economy: a financial index (IBEX35), a commodity (crude oil price in euros), a foreign exchange index (EUR/USD),… read more here.

Keywords: power spectrum; period; wavelet power; spectrum cross ... See more keywords
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Nonlinear evolution of oblique whistler waves in radiation belts

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Published in 2017 at "Astrophysics and Space Science"

DOI: 10.1007/s10509-016-3003-x

Abstract: Magnetic power spectrum and formation of coherent structures have been investigated in the present work applicable to Van Allen radiation belt. The nonlinear interaction of high frequency oblique whistler wave and low frequency magnetosonic wave… read more here.

Keywords: nonlinear evolution; magnetic power; spectrum; oblique whistler ... See more keywords
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BB mode angular power spectrum of CMB from massive gravity

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Published in 2021 at "Astrophysics and Space Science"

DOI: 10.1007/s10509-021-04017-2

Abstract: The primordial massive gravitational waves are placed in the squeezed vacuum state and corresponding $BB$-mode correlation angular power spectrum of the cosmic microwave background is obtained for various slow roll inflation models. The angular power… read more here.

Keywords: mode angular; angular power; power spectrum;
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Primordial power spectrum from the Dapor–Liegener model of loop quantum cosmology

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Published in 2018 at "General Relativity and Gravitation"

DOI: 10.1007/s10714-018-2413-1

Abstract: We compute the predictions for the power spectrum of scalar perturbations from a recent new proposal for the effective Hamiltonian of loop quantum cosmology. The model provides an attractive picture of the early cosmos, in… read more here.

Keywords: cosmology; quantum cosmology; power spectrum; loop quantum ... See more keywords
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Power spectrum for perturbations in an inflationary model for a closed universe

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Published in 2022 at "General Relativity and Gravitation"

DOI: 10.1007/s10714-022-02918-3

Abstract: We derive the power spectrum of primordial quantum fluctuations in an inflationary universe for curvature parameter $${\mathcal {K}}=1$$ K = 1 . This is achieved through a Born–Oppenheimer type of approximation scheme from the Wheeler–DeWitt… read more here.

Keywords: power spectrum; model closed; spectrum perturbations; model ... See more keywords
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Nonlinear power spectrum in clustering and smooth dark energy models beyond the BAO scale

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Published in 2019 at "Journal of Astrophysics and Astronomy"

DOI: 10.1007/s12036-019-9584-3

Abstract: We study the nonlinear effects of the clustering and smooth quintessence. We present numerical and also approximate semi-analytical expressions of nonlinear power spectrum both for clustering and smooth dark energy models beyond the Baryon Acoustic… read more here.

Keywords: dark energy; nonlinear power; energy models; power spectrum ... See more keywords
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Scale Invariance of Power Spectrum in Sediment Transport Mechanics

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Published in 2018 at "National Academy Science Letters"

DOI: 10.1007/s40009-018-0616-3

Abstract: Flume experiments were carried over a curvilinear mobile sand bed and over a vegetated sand bed to scale the power spectra variation in the longitudinal velocity spectrum of turbulence flow. Instantaneous three dimensional velocities were… read more here.

Keywords: invariance power; scale invariance; mechanics; spectrum ... See more keywords
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A Method of Estimating the Partial Power Spectrum of a Bivariate Point Process and an Application to a Neurophysiological Data Set

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Published in 2020 at "Journal of Statistical Theory and Practice"

DOI: 10.1007/s42519-020-00105-8

Abstract: In this paper, we present a method of estimating the partial power spectrum of a bivariate point process. The method is based on the simple and cross-periodograms which are smoothed by applying a simple averaging… read more here.

Keywords: estimating partial; partial power; spectrum bivariate; method ... See more keywords
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Reconstructing a non-linear interaction in the dark sector with cosmological observations

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Published in 2021 at "Physics of the Dark Universe"

DOI: 10.1016/j.dark.2021.100784

Abstract: Abstract In this work we model two non-linear directly interacting scenarios in dark sector of the universe with the dimensionless parameter α and β , which dominate the energy exchange between dark energy and dark… read more here.

Keywords: dark sector; power spectrum; interaction;
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Response transmissibility versus power spectrum density transmissibility: Dynamic property analysis and comparison

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Published in 2019 at "Journal of Sound and Vibration"

DOI: 10.1016/j.jsv.2019.04.019

Abstract: Abstract The concept of transmissibility has been developed rapidly for operational modal analysis (OMA) in recent years. In general, there are two kinds of transmissibility: response transmissibility (RT) and power spectrum density transmissibility (PSDT). Based… read more here.

Keywords: input; density transmissibility; response transmissibility; spectrum density ... See more keywords