Related papers: The disc instability model: original recipe and ad…
Previous simulations of cataclysmic variables studied either the quiescence, or the outburst state in multiple dimensions or they simulated complete outburst cycles in one dimension using simplified models for the gravitational torques. We…
We analyse numerically a pinch-type instability in a semi-infinite planar layer of inviscid conducting liquid bounded by solid walls and carrying a uniform electric current. Our model is as simple as possible but still captures the salient…
The use of available disturbance predictions within a nominal model predictive control formulation is studied. The main challenge that arises is the loss of recursive feasibility and stability guarantees when a persistent disturbance is…
Observations of accreting systems often show significant variability (10-20 percent of accretion luminosity) on timescales much longer than expected for the disc regions releasing most of the luminosity. We propose an explicit physical…
Observed IR excesses indicate that protoplanetary discs evolve slowly for the majority of their lifetime before losing their near- and mid-IR excesses on short timescales. Photoevaporation models can explain this "two-timescale" nature of…
We investigated the Rayleigh-Plateau instability at the interface between two immiscible liquids of equal viscosity using molecular dynamics simulations. Two types of initial conditions were considered, one with an imposed single-mode…
Dynamic factor models are often estimated by point-estimation methods, disregarding parameter uncertainty. We propose a method accounting for parameter uncertainty by means of posterior approximation, using variational inference. Our…
The Jeans instability is analyzed for dense magnetohydrodynamic plasmas with intrinsic magnetization, the latter due to collective electron spin effects. Furthermore, effects of electron tunneling as well as the Fermi pressure are included.…
The recurrent outbursts that characterise low-mass binary systems reflect thermal state changes in their associated accretion discs. The observed outbursts are connected to the strong variation in disc opacity as hydrogen ionises near 5000…
Theory of random processes provides an attractive mathematical tool to describe the fluctuating signal from accreting sources, such as active galactic nuclei and Galactic black holes observed in X-rays. These objects exhibit featureless…
The impact of quenched disorder on deterministic diffusion in chaotic dynamical systems is studied. As a simple example, we consider piecewise linear maps on the line. In computer simulations we find a complicated scenario of multiple…
Some general properties of the advective-acoustic instability are described and understood using a toy model which is simple enough to allow for analytical estimates of the eigenfrequencies. The essential ingredients of this model, in the…
We present local simulations that verify the linear streaming instability that arises from aerodynamic coupling between solids and gas in protoplanetary disks. This robust instability creates enhancements in the particle density in order to…
I discuss some aspects of the Disc Instability Model applied to outbursts in various types of binary systems. I lament the general lack of interest in the subject.
We investigate the convective stability of a thin, infinite fluid layer with a rectangular cross-section, subject to imposed heat fluxes at the top and bottom and fixed temperature along the vertical sides. The instability threshold depends…
Sphere packings are essential to the development of physical models for powders, composite materials, and the atomic structure of the liquid state. There is a strong scientific need to be able to assess the fit of packing models to data,…
Using zoom-simulations carried out with the adaptive mesh-refinement code RAMSES with a dynamic range of up to $2^{27} \approx 1.34 \times 10^8$ we investigate the accretion profiles around six stars embedded in different environments…
The buoyancy-induced parallel flow in a vertical cylindrical porous layer is analysed. A radial thermal gradient caused by a uniformly distributed heat source is assumed to induce the buoyant flow. The layer boundaries are modelled as…
Extensive numerical evidence shows that the assimilation of observations has a stabilizing effect on unstable dynamics, in numerical weather prediction and elsewhere. In this paper, we apply mathematically rigorous methods to showing why…
We study the dynamics of a twisted tilted disc under the influence of an external radiation field. Assuming the effect of absorption and reemission/scattering is that a pressure is applied to the disc surface where the local optical depth…