Related papers: Primary Initiation of Submarine Canyons
A key result of hydrogravitational dynamics cosmology relevant to astrobiology is the early formation of vast numbers of hot primordial-gas planets in million-solar-mass clumps as the dark matter of galaxies and the hosts of first life.…
The long-term retention of substantial atmospheres in close-in exoplanets presents a major challenge to classical hydrodynamic escape theory, which predicts rapid mass loss under intense stellar irradiation. In this work, we propose a fully…
The first discovered extrasolar worlds -- giant, ``hot Jupiter'' planets on short-period orbits -- came as a surprise to solar-system-centric models of planet formation, prompting the development of new theories for planetary system…
Despite their ubiquity, the origin of cosmic magnetic fields remains unknown. Various mechanisms have been proposed for their existence including primordial fields generated by inflation, or amplification and injection by compact…
The timeline of the Earth's history reveals quasi-periodicity of the geological record over the last 542 Myr, on timescales close, in the order of magnitude, to 1 Myr. What is the origin of this quasi-periodicity? What is the nature of the…
Some recently discovered short-period Earth to Neptune sized exoplanets (super Earths) have low observed mean densities which can only be explained by voluminous gaseous atmospheres. Here, we study the conditions allowing the accretion and…
Using radiation hydrodynamics simulations, we explore the evolution of circumplanetary disks around wide-orbit proto-gas giants. At large distances from the star (~100 AU), gravitational instability followed by disk fragmentation can form…
The formation of the Earth's core is a consequence of planetary accretion and processes in the Earth's interior. The mechanical process of planetary differentiation is likely to occur in large, if not global, magma oceans created by the…
The primordial internal structures of gas giant planets are unknown. Often giant planets are modeled under the assumption that they are adiabatic, convective, and homogeneously mixed, but this is not necessarily correct. In this work, we…
Hot Jupiters have proven themselves to be a rich class of exoplanets which test our theories of planetary evolution and atmospheric dynamics under extreme conditions. Here, we present three-dimensional magnetohydrodynamic simulations and…
We explore the role of dynamics in shaping planetary system multiplicities, focussing on two particular problems. (1) We propose that the lack of close-in super-Earths in hot Jupiter systems is a signature of the migration history of the…
Protoplanets of Super-Earth sizes may get trapped in convergence zones for planetary migration and form gas giants there. These growing planets undergo accretion heating, which triggers a hot-trail effect that can reverse migration…
We develop a phenomenological theory that aims to account for the origin of the large eccentricities of extrasolar planets and that of the small eccentricities in the solar system, the preference for apsidal alignment in non-resonant…
The omnipresence of super-Earths suggests that they are able to be retained in natal disks around low-mass stars, whereas exoplanets' mass distribution indicates that some cores have transformed into gas giants through runaway gas accretion…
Tidal Downsizing is the modern version of the Kuiper (1951) scenario of planet formation. Detailed simulations of self-gravitating discs, gas fragments, dust grain dynamics, and planet evolutionary calculations are summarised here and used…
Planets with masses larger than about 0.1 Earth-masses undergo rapid inward migration (type I migration) in a standard protoplanetary disk. Recent magnetohydrodynamical simulations revealed the presence of magnetically driven disk winds,…
The origin of the Uranian satellite system remains uncertain. The four major satellites have nearly circular, co-planar orbits and the ratio of the satellite system and planetary mass resembles Jupiter's satellite system, suggesting the…
We investigate the origins of cold sub-Saturns (CSS), an exoplanetary population inferred from microlensing surveys. If confirmed, these planets would rebut a theorised gap in planets' mass distribution between those of Neptune and Jupiter…
I show that a cumulative contraction or expansion must result from repetitive tidal action in a curved stress field, depending on the direction of the curvature. The resulting expansion of solid materials onboard deep space probes and the…
During their formation, emerging protoplanets tidally interact with their natal disks. Proto-gas-giant planets, with Hills radius larger than the disk thickness, open gaps and quench gas flow in the vicinity of their orbits. It is usually…