Arjun Berera

Thermal enhancement of inflationary magnetic fields

Arjun Berera, Suddhasattwa Brahma, Zizang Qiu, Rudnei O. Ramos

Abstract We investigate primordial magnetogenesis by assuming the gauge field is prepared in a thermal state during inflation rather than the standard Bunch-Davies vacuum. The temperature 𝒯 introduces a physical scale that breaks conformal invariance at the level of the state while …

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Editorial: Large long-lived vertical wind oscillations in the mesosphere and thermosphere regions

Jorge L. Chau, Anasuya Aruliah, John Meriwether, Miguel F. Larsen et autres

The mesosphere and lower thermosphere (MLT) regions, spanning altitudes between approximately 60 and 200 km, represent a highly dynamic transition zone between the Earth's lower atmosphere and the near-space environment. Historically, atmospheric models and observational interpretations have operated under the assumption of …

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Heterotic warm inflation

Arjun Berera, Heliudson Bernardo, Suddhasattwa Brahma, Jaime Calderón-Figueroa et autres

A bstract We propose a two-field model of warm inflation motivated by a heterotic string construction, involving an axion and a dilaton-like scalar field with non-trivial kinetic mixing. Gauge-field interactions generate dissipation and thermal corrections affecting both fields. A systematic numerical analysis …

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Measuring Coherent Radio and Microwave Photons from the Solar Corona

Liang Chen, Zizang Qiu, Tom Kephart, Arjun Berera

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Thermal enhancement of inflationary magnetic fields

Arjun Berera, Suddhasattwa Brahma, Zizang Qiu, Rudnei O. Ramos

We investigate primordial magnetogenesis by assuming the gauge field is prepared in a thermal state during inflation rather than the standard Bunch-Davies vacuum. The temperature $\mathcal{T}$ introduces a physical scale that breaks conformal invariance at the level of the state while preserving …

gb, in, br (code pays fourni par la source)

Choice of Quantum Vacuum for Inflation Observables

Melo Wood-Saanaoui, Rudnei O. Ramos, Arjun Berera

We investigate the modifications to inflationary observables that arise when adopting an α-vacuum instead of the standard Bunch–Davies vacuum for quantum fluctuations during inflation. Within the Starobinsky inflationary model, we compute and compare the scalar spectral index, its running, and the running …

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Choice of Quantum Vacuum for Inflation Observables

Melo Wood-Saanaoui, Rudnei O. Ramos, Arjun Berera

We investigate the modifications to inflationary observables that arise when adopting an $α$-vacuum instead of the standard Bunch--Davies vacuum for quantum fluctuations during inflation. Within the Starobinsky inflationary model, we compute and compare the scalar spectral index, its running, and the running …

Measuring the effect of spatial dimension on hydrodynamic turbulence using direct numerical simulation

Richard D. J. G. Ho, Daniel Lynn Clark, Andres Armua, Xichao Yang et autres

We perform direct numerical simulation of the incompressible Navier-Stokes equation with forcing at different spatial dimensions and measure turbulent and chaotic properties. Lyapunov exponents, $λ$, decrease with dimension, and $λ< 0$ for all simulations in six-dimensions up to $Re = 40$. These …

Rogue vertical drafts in the mesosphere and lower thermosphere: evidence and implications

Jorge Luis Chau, Arjun Berera, Devin Huyghebaert

Observational evidence of extreme vertical velocities ( | w | ≥ 12.5 m/s and at times greater than 50 m/s) in the mesosphere and lower thermosphere (MLT), has emerged in recent years. We refer to these events as Rogue Vertical Drafts (RVDs). …

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The early universe is ACT -ing warm

Arjun Berera, Suddhasattwa Brahma, Zizang Qiu, Rudnei O. Ramos et autres

Abstract The recently released data from the 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 simplest models of inflation coming from particle physics (for …

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The early universe is $\textit{ACT}$-ing $\textit{warm}$

Arjun Berera, Suddhasattwa Brahma, Rudnei O. Ramos, Gabriel Rodrigues

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 simplest models of inflation coming from particle physics (for instance, …

Measuring Coherent Radio and Microwave Photons from the Solar Corona

Liang Chen, Thomas W. Kephart, Arjun Berera

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 quantum states via the inverse HOM effect are …