Related papers: Formation of Planets by Hydrogravitational Dynamic…
Gravitational hydrodynamics acknowledges that hydrodynamics is essentially nonlinear and viscous. In the plasma, at $z=5100$, the viscous length enters the horizon and causes fragmentation into plasma clumps surrounded by voids. The latter…
We investigate formation mechanisms for icy super-Earth mass planets orbiting at 2-20 AU around 0.1-0.5 solar mass stars. A large ensemble of coagulation calculations demonstrates a new formation channel: disks composed of large…
We describe high resolution Smoothed Particle Hydrodynamics (SPH) simulations of three approximately $M_*$ field galaxies starting from \LCDM initial conditions. The simulations are made intentionally simple, and include photoionization,…
Direct imaging observations of planets revealed that wide-orbit ($>10$ au) giant planets exist even around subsolar-metallicity host stars and do not require metal-rich environments for their formation. A possible formation mechanism of…
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…
The current observational evidences suggest there are about hundred billion galaxies in the observable universe and within each, on an average, about hundred billion stars. But no cosmological model indicates as to why there are these many…
The current understanding of galaxy formation is that it proceeds in a 'bottom up' way, with the formation of small clumps of gas and stars that merge hierarchically until giant galaxies are built up. The baryonic gas loses the thermal…
According to the sequential accretion model, giant planet formation is based first on the formation of a solid core which, when massive enough, can gravitationally bind gas from the nebula to form the envelope. In order to trigger the…
As gas giant planets evolve, they may scatter other planets far from their original orbits to produce hot Jupiters or rogue planets that are not gravitationally bound to any star. Here, we consider planets cast out to large orbital…
Doppler surveys have shown that more massive stars have significantly higher frequencies of giant planets inside $\sim$ 3 AU than lower mass stars, consistent with giant planet formation by core accretion. Direct imaging searches have begun…
Evidence is summarized that suggests that when a protogalaxy collapses, a fraction $f$ of its gas fails to heat to the virial temperature, where $f$ is large for haloes less massive than the value $M^*$ associated with $L^*$ galaxies. Stars…
Star and planet formation are inextricably linked. In the earliest phases of the collapse of a protostar a disc forms around the young star and such discs are observed for the first several million years of a star's life. It is within these…
Extreme conditions in natural flows are examined, starting with a turbulent big bang. A hydro-gravitational-dynamics cosmology model is adopted. Planck-Kerr turbulence instability causes Planck-particle turbulent combustion. Inertial-vortex…
Dynamical considerations, presented herein via analytic scalings and numerical experiments, imply that Earth-mass planets accreting in regions that become habitable zones of M dwarf stars form within several million years. Temperatures in…
Galaxies can be classified in two broad sequences which are likely to reflect their formation mechanism. The `main sequence', consisting of spirals, irregulars and all dwarf galaxies, is probably produced by gas settling within dark matter…
As stellar compositions evolve over time in the Milky Way, so will the resulting planet populations. In order to place planet formation in the context of Galactic chemical evolution, we make use of a large ($N = 5\,325$) stellar sample…
The recent detection of planets around very low mass stars raises the question of the formation, composition and potential habitability of these objects. We use planetary system formation models to infer the properties, in particular their…
We present a simple theoretical framework for massive galaxies at high redshift, where the main assembly and star formation occurred, and report on the first cosmological simulations that reveal clumpy disks consistent with our analysis.…
Young galaxies are clumpy, gas-rich, and highly turbulent. Star formation appears to occur by gravitational instabilities in galactic disks. The high dispersion makes the clumps massive and the disks thick. The star formation rate should be…
Using a new physical model for star formation (Padoan 1995) we have tested the possibility that globular clusters (GCs) are formed from primordial mass fluctuations, whose mass scale ($10^8$ - $10^9$ M$_{\odot}$) is selected out of a CDM…