Related papers: Stable causality of Black Saturns
Let $\cal R$ be an ordered vector space over an ordered division ring. We prove that every definable set $X$ is a finite union of relatively open definable subsets which are definably simply-connected, settling a conjecture from [5]. The…
We investigate the appearance of closed timelike curves in quotients of plane waves along spacelike isometries. First we formulate a necessary and sufficient condition for a quotient of a general spacetime to preserve stable causality. We…
We find an interesting fact that fictitious retrograde co-orbitals of Saturn, or small bodies inside the retrograde 1:1 resonance with Saturn, are highly unstable in our numerical simulations. It is shown that in the presence of Jupiter,…
We argue that pulsars may be spin-polarized neutron stars, i.e. cosmic permanent magnets. This would simply explain several observational facts about pulsars, including the 'beacon effect' itself i.e. the static/stable misalignment of…
We consider perturbations in a cosmological model with a small coupling between dark energy and dark matter. We prove that the stability of the curvature perturbation depends on the type of coupling between dark sectors. When the dark…
We prove an orbital stability theorem of KdV $n$-solitons with explicit phase shifts in the soliton region with cones around the $x$-axis and lines determined by bound states of the KdV $n$-solitons removed.
Astrophysics gives evidence for the existence of Dark Matter and puts constraints on its nature. The Cold Dark Matter model has become "standard" cosmology combined with a cosmological constant. There are indications that "Cold" Dark Matter…
We survey some recent development in the stability theory of klt singularities. The main focus is on the solution of the stable degeneration conjecture.
We present a new stationary, asymptotically flat solution of 5D Einstein-Maxwell gravity describing a Saturn-like black object: a rotating black hole surrounded by a rotating dipole black ring. The solution is generated by combining the…
A precise definition of a black hole has long been absent in causal set theory. I first show that the local finiteness of the theory cannot be interpreted as a complete discretization condition, and the theory still admits continua, which I…
It has recently been shown that there exist stable inhomogeneous neutral black strings in higher dimensional gravity. These solutions were motivated by the fact that the corresponding homogeneous solutions are unstable. We show that there…
The sterile neutrino solutions to different irregular results and observations in neutrino physics are studied. It is pointed out that introducing sterile neutrinos helps to solve simultaneously the observed anomalies. It is argued that…
We study just infinite algebras which remain so upon extension of scalars by arbitrary field extensions. Such rings are called stably just infinite. We show that just infinite rings over algebraically closed fields are stably just infinite…
Normal mode oscillations in Saturn excite density and bending waves in the C Ring, providing a valuable window into the planet's interior. Saturn's fundamental modes (f modes) excite the majority of the observed waves, while…
We explore via linearized perturbation theory the Gregory-Laflamme instability of the black string solutions of Einstein's equations with negative cosmological constant recently discussed in literature. Our results indicate that the black…
The stability of photon trajectories in models of the Universe that have constant spatial curvature is determined by the sign of the curvature: they are exponentially unstable if the curvature is negative and stable if it is positive or…
We offer a mathematically rigorous basis for the widely held suspicion that full black hole evaporation is in tension with predictability. Based on conditions expressing the global causal structure of evaporating black hole spacetimes, we…
We introduce a new class of self-sustained states, which may exist as single solitons or form multisoliton clusters, in driven passive cylindrical microresonators. Remarkably, such states are stabilized by the radiation they emit, which…
The immense tidal forces of massive black holes can rip apart stars that come too close to them. As the resulting stellar debris spirals inwards, it heats up and emits x-rays when near the black hole. Here, we report the discovery of an…
Tidal dissipation inside giant planets is important for the orbital evolution of their natural satellites. It is conventionally treated by parameterized equilibrium tidal theory, in which the tidal torque declines rapidly with distance, and…