相关论文: Multiverse Predictions for Habitability: Fraction …
We explore some of the ramifications arising from superflares on the evolutionary history of Earth, other planets in the Solar system, and exoplanets. We propose that the most powerful superflares can serve as plausible drivers of…
Gamma-Ray Bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of GRBs…
The relative abundances of exotic environments provides us with (uninformed) bounds on the habitability of those environments relative to our own, on the basis that our presence here is not too atypical. For instance, since red stars…
Microorganisms live in environments that inevitably fluctuate between mild and harsh conditions. As harsh conditions may cause extinctions, the rate at which fluctuations occur can shape microbial communities and their diversity, but we…
Multispecies ecosystems modelled by generalized Lotka-Volterra equations exhibit stationary population abundances, where large number of species often coexist. Understanding the precise conditions under which this is at all feasible and…
We present a model for evolution and extinction in large ecosystems. The model incorporates the effects of interactions between species and the influences of abiotic environmental factors. We study the properties of the model by approximate…
A gap in exoplanets' radius distribution has been widely attributed to the photo-evaporation threshold of their progenitors' gaseous envelope. Giant impacts can also lead to substantial mass-loss. The outflowing gas endures tidal torque…
Gamma-ray bursts and ultra-high-energy cosmic rays provide an important testing ground for fundamental physics. A simple-minded analysis of some gamma-ray bursts would lead to a huge estimate of the overall energy emitted, and this…
If gamma-ray bursts originate in our Galaxy, they probably involve violent disturbances in the magnetospheres of neutron stars. Any event of this kind is likely to trigger the sudden expulsion of magnetic flux and plasma at relativistic…
The 'event' that triggers a gamma ray burst cannot last for more than a few seconds. This is, however, long compared with the dynamical timescale of a compact stellar-mass object ($\sim 10^{-3}$ seconds). Energy is assumed to be released as…
We discuss some the effects of local gamma-ray bursts on the earth's atmosphere. A rough calculation of the fraction of ozone destruction by catalytic $NO_{x}$ cycles is given, which in turn serves to argue how the large flux of gammas from…
The chemical enrichment of the Universe; the mass spectrum of planetary nebulae, white dwarfs and gravitational wave progenitors; the frequency distribution of Type I and II supernovae; the fate of exoplanets ... a multitude of phenomena…
When density fluctuations collapse gravitationally out of the expanding cosmological background universe to form galaxies, the secondary energy release which results can affect their subsequent evolution profoundly. We focus here on the…
Globally disruptive events include asteroid/comet impacts, large igneous provinces and glaciations, all of which have been considered as contributors to mass extinctions. Understanding the overall relationship between the timings of the…
Magnitude-limited samples of spiral galaxies drawn from the Ursa Major and Pisces clusters are used to determine their extinction properties as a function of inclination. Imaging photometry is available for 87 spirals in B,R,I and K' bands.…
We present a semi-analytic treatment of galactic winds within high resolution, large scale cosmological N-body simulations of a LCDM Universe. The evolution of winds is investigated by following the expansion of supernova driven…
Climate-mediated changes in the spatiotemporal distribution of thermal stress can destabilize animal populations and promote extinction risk. Using quantile, spectral, and wavelet analyses of temperature projections from the latest…
Highly-diverse ecosystems exhibit a broad distribution of population sizes and species turnover, where species at high and low abundances are exchanged over time. We show that these two features generically emerge in the fluctuating phase…
Introducing the effect of extinction into the so-called replicator equations in mathematical biology, we construct a general model of ecosystems. The present model shows mass extinction by its own extinction dynamics when the system…
We present in this work a unified, quantitative synthesis of analytical and numerical calculations of the effects that could be caused on Earth by a Gamma-Ray Burst (GRB), considering atmospheric and biological implications. The main…