Arjun Berera
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View article: The early universe is $\textit{ACT}$-ing $\textit{warm}$
The early universe is $\textit{ACT}$-ing $\textit{warm}$ Open
The recently released data from the $\textit{Atacama Cosmology Telescope}$ (ACT) confirms that the primordial scalar spectrum is extremely flat. This, together with current upper bounds on the tensor-to-scalar ratio, implies that the simpl…
View article: Measuring Coherent Radio and Microwave Photons from the Solar Corona
Measuring Coherent Radio and Microwave Photons from the Solar Corona Open
The rates of production of radio/microwave N-identical photons states |N> from stimulated emission in the solar atmosphere are estimated. Effects of various decohering factors are shown to be small. Ground based measurements of these quant…
View article: Chaotic Measures as an Alternative to Spectral Measures for Analysing Turbulent Flow
Chaotic Measures as an Alternative to Spectral Measures for Analysing Turbulent Flow Open
Turbulence has associated chaotic features. In the past couple of decades, there has been growing interest in the study of these features as an alternative means of understanding turbulent systems. Our own input to this effort is in contri…
View article: Chaotic measures as an alternative to spectral measures for analysing turbulent flow
Chaotic measures as an alternative to spectral measures for analysing turbulent flow Open
Turbulence has associated chaotic features. In the past couple of decades there has been growing interest in the study of these features as an alternative means of understanding turbulent systems. Our own input to this effort has been in c…
View article: Astrophysically sourced quantum coherent photonic signals
Astrophysically sourced quantum coherent photonic signals Open
Stimulated emission is shown to be robust in stars. Through Bose enhancement this produces quantum states of aligned, monochromatic photons somewhat similar to a laser. The probability of creating such states is computed. We show that from…
View article: Astrophysically sourced quantum coherent photonic signals
Astrophysically sourced quantum coherent photonic signals Open
Stimulated emission is shown to be robust in stars. Through Bose enhancement this produces quantum states of aligned, monochromatic photons similar to a laser. The probability of creating such states is computed. We show that from the sola…
View article: The Warm Inflation Story
The Warm Inflation Story Open
Warm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from in…
View article: The warm inflation story
The warm inflation story Open
Warm inflation has normalized two ideas in cosmology, that in the early universe the initial primordial density perturbations generally could be of classical rather than quantum origin and that during inflation, particle production from in…
View article: Parameter study of decaying magnetohydrodynamic turbulence
Parameter study of decaying magnetohydrodynamic turbulence Open
It is well known that helical magnetohydrodynamic (MHD) turbulence exhibits an inverse transfer of magnetic energy from small to large scales, which is related to the approximate conservation of magnetic helicity. Recently, several numeric…
View article: Looking inside the Swampland from Warm Inflation: Dissipative Effects in De Sitter Expansion
Looking inside the Swampland from Warm Inflation: Dissipative Effects in De Sitter Expansion Open
This paper reviews the theoretical and phenomenological implications of the swampland conjectures from the perspective of inflationary cosmology, focusing on warm inflation. We demonstrate how the swampland conjectures appear to favor the …
View article: Detecting Microbiology in the Upper Atmosphere: Relative-Velocity Filtered Sampling
Detecting Microbiology in the Upper Atmosphere: Relative-Velocity Filtered Sampling Open
The purpose of this article is to reopen from a practical perspective the question of the extent in altitude of Earth's biosphere. We make a number of different suggestions for how searches for biological material could be conducted in the…
View article: Parameter study of decaying magnetohydrodynamic turbulence
Parameter study of decaying magnetohydrodynamic turbulence Open
It is well known that helical magnetohydrodynamic (MHD) turbulence exhibits an inverse transfer of magnetic energy from small to large scales, which is related to the approximate conservation of magnetic helicity. Recently, several numeric…
View article: Universal signature of quantum entanglement across cosmological distances
Universal signature of quantum entanglement across cosmological distances Open
Although the paradigm of inflation has been extensively studied to demonstrate how macroscopic inhomogeneities in our Universe originate from quantum fluctuations, most of the established literature ignores the crucial role that entangleme…
View article: Quantum corrections to the primordial tensor spectrum: open EFTs & Markovian decoupling of UV modes
Quantum corrections to the primordial tensor spectrum: open EFTs & Markovian decoupling of UV modes Open
A bstract Perturbative quantum corrections to primordial power spectra are important for testing the robustness and the regime of validity of inflation as an effective field theory. Although this has been done extensively for the density p…
View article: Viability of quantum communication across interstellar distances
Viability of quantum communication across interstellar distances Open
The possibility of achieving quantum communication using photons across interstellar distances is examined. For this, different factors are considered that could induce decoherence of photons, including the gravitational field of astrophys…
View article: Critical transition to a non-chaotic regime in isotropic turbulence
Critical transition to a non-chaotic regime in isotropic turbulence Open
We study the properties of homogeneous and isotropic turbulence in higher spatial dimensions through the lens of chaos and predictability using numerical simulations. We employ both direct numerical simulations and numerical calculations o…
View article: Quantum coherence of photons to cosmological distances
Quantum coherence of photons to cosmological distances Open
We identify potential sources of decoherence for U ( 1 ) gauge bosons from a cosmological standpoint. Besides interactions with different species in the cosmological medium, we also consider effects due to the expansion of the Universe, wh…
View article: Universal signature of quantum entanglement across cosmological distances
Universal signature of quantum entanglement across cosmological distances Open
Although the paradigm of inflation has been extensively studied to demonstrate how macroscopic inhomogeneities in our universe originate from quantum fluctuations, most of the established literature ignores the crucial role that entangleme…
View article: Chaotic measure of the transition between two- and three-dimensional turbulence
Chaotic measure of the transition between two- and three-dimensional turbulence Open
Using direct numerical simulation we study the behavior of the maximal Lyapunov exponent in thin-layer turbulence, where one dimension of the system is constrained geometrically. Such systems are known to exhibit transitions from fully thr…
View article: Thermal, trapped and chromo-natural inflation in light of the swampland criteria and the trans-Planckian censorship conjecture
Thermal, trapped and chromo-natural inflation in light of the swampland criteria and the trans-Planckian censorship conjecture Open
We consider thermal, trapped and chromo-natural inflation in light of the swampland criteria and the Trans-Planckian Censorship Conjecture (TCC). Since thermal inflation occurs at energies low compared to those of Grand Unification, it is …
View article: Effect of spatial dimension on a model of fluid turbulence
Effect of spatial dimension on a model of fluid turbulence Open
A numerical study of the $d$ -dimensional eddy damped quasi-normal Markovian equations is performed to investigate the dependence on spatial dimension of homogeneous isotropic fluid turbulence. Relationships between structure functions and…
View article: Towards a reliable effective field theory of inflation
Towards a reliable effective field theory of inflation Open
We present the first quantum field theory model of inflation that is renormalizable in the matter sector, with a super-Hubble inflaton mass and sub-Planckian field excursions, which is thus technically natural and consistent with a high-en…
View article: Superfast amplification and superfast nonlinear saturation of perturbations as a mechanism of turbulence
Superfast amplification and superfast nonlinear saturation of perturbations as a mechanism of turbulence Open
View article: Quantum coherence to interstellar distances
Quantum coherence to interstellar distances Open
Quantum coherence could be sustained up to interstellar distances. It is shown that the photon mean free path in certain regions of the electromagnetic spectrum, such as within the radio or x-ray ranges, could allow sustaining of the quant…
View article: On the force of vertical winds in the upper atmosphere
On the force of vertical winds in the upper atmosphere Open
For many decades vertical winds have been observed at high altitudes of the Earth's atmosphere, in the mesosphere and thermosphere layers. These observations have been used with a simple one dimensional model to make estimates of possible …
View article: Homogeneous isotropic turbulence in four spatial dimensions
Homogeneous isotropic turbulence in four spatial dimensions Open
Direct numerical simulation is performed for the forced Navier–Stokes equation in four spatial dimensions. Well equilibrated, long time runs at sufficient resolution were obtained to reliably measure spectral quantities, the velocity deriv…
View article: Fluctuations of Lyapunov exponents in homogeneous and isotropic turbulence
Fluctuations of Lyapunov exponents in homogeneous and isotropic turbulence Open
In the context of the analysis of the chaotic properties of homogeneous and isotropic turbulence, direct numerical simulations are used to study the fluctuations of the finite-time Lyapunov exponent (FTLE) and its relation to the Reynolds …
View article: Trans-Planckian censorship and other swampland bothers addressed in warm inflation
Trans-Planckian censorship and other swampland bothers addressed in warm inflation Open
The implications of the recently proposed Trans-Planckian censorship\nconjecture (TCC) are analyzed in the context of warm inflation. It is found\nthat for a single-stage accelerated expansion the constraints imposed by the\ncensorship are…
View article: Information production in homogeneous isotropic turbulence
Information production in homogeneous isotropic turbulence Open
We study the Reynolds number scaling of the Kolmogorov-Sinai entropy and attractor dimension for three-dimensional homogeneous isotropic turbulence through the use of direct numerical simulation. To do so, we obtain Lyapunov spectra for a …
View article: Formulating the Kramers problem in field theory
Formulating the Kramers problem in field theory Open
The escape problem is defined in the context of quantum field theory. The\nescape rate is explicitly derived for a scalar field governed by\nfluctuation-dissipation dynamics, through generalizing the standard Kramers\nproblem. In the prese…