Related papers: A causally connected superluminal Warp Drive space…
An overwhelming majority of galactic spiral arms trail with respect to the rotation of the galaxy, though a small sample of leading spiral arms has been observed. The formation of these leading spirals is not well understood. Here we show,…
Recent observations have shown that at least some close-in exoplanets maintain eccentric orbits despite tidal circularization timescales that are typically shorter than stellar ages. We explore gravitational interactions with a distant…
In stark contrast to their laboratory and terrestrial counterparts, the cosmic jets appear to be very stable. We propose that the reason behind this remarkable property is the loss of causal connectivity across these jets, caused by their…
We report on results of N-body simulations aimed at testing the hypothesis that galaxies in X-ray emitting (i.e., virialized) Compact Groups are not tidally stripped when they are embedded in a common, massive, quiescent dark matter halo.…
We investigate the internal controllability of the wave equation with structural damping on the one dimensional torus. We assume that the control is acting on a moving point or on a moving small interval with a constant velocity. We prove…
In recent years an increasing number of observational studies have hinted at the presence of warps in protoplanetary discs, however a general comprehensive description of observational diagnostics of warped discs was missing. We performed a…
It is shown that causally simple inextendible spacetimes are hole-free, thus confirming the expectation that causal simplicity removes holes from spacetime. This result is optimal in the sense that causal simplicity cannot be weakened to…
We show that superconducting correlations in the presence of non-zero condensate velocity can mediate the peculiar interaction between localized spins that breaks the global inversion symmetry of magnetic moments. The proposed interaction…
It is now clear that the stars in the Solar neighbourhood display large-scale coherent vertical breathing motions. At the same time, Milky Way-like galaxies experience tidal interactions with satellites/companions during their evolution.…
We propose superluminal solitons residing in the momentum gap (k-gap) of nonlinear photonic time-crystals. These gap solitons are structured as plane-waves in space while being periodically self-reconstructing wavepackets in time. The…
If Lorentz invariance is only an approximate property of equations describing a sector of matter above some critical distance scale, the speed of light c will not necessarily be the only critical speed in vacuum. Superluminal sectors of…
Can the direction of time and the causal structure of space-time be inferred from operational principles? Causal models and tensor networks offer complementary perspectives: the former encodes cause-effect relations via directed graphs,…
Although a plethora of techniques are now available for controlling the group velocity of an optical wave packet, there are very few options for creating accelerating or decelerating wave packets whose group velocity varies controllably…
In an equilibrium axisymmetric galactic disc, the mean galactocentric radial and vertical velocities are expected to be zero everywhere. In recent years, various large spectroscopic surveys have however shown that stars of the Milky Way…
The apparent superluminal growth in the size of a sufficiently large part of the universe can be ascribed to the special relativistic effect of time dilation.
We establish a correspondence between the gravitational phase space at null infinity and the subleading phase space near a finite-distance null hypersurface, such as a black hole horizon. Within this framework, we identify the celestial…
Within the framework of general relativity, we investigate the tidal acceleration of astrophysical jets relative to the central collapsed configuration ("Kerr source"). We neglect electromagnetic forces throughout. The rest frame of the…
Nonlinear waves are a robust phenomenon observed in complex systems ranging from mechanics to ecology. Fronts are fundamental due to their robustness against perturbations and capacity to propagate one state over another. Controlling and…
We study the radiation-driven warping of accretion discs in the context of X-ray binaries. The latest evolutionary equations are adopted, which extend the classical alpha theory to time-dependent thin discs with non-linear warps. We also…
The stability of cosmological event and Cauchy horizons of spacetimes associated with plane symmetric domain walls are studied. It is found that both horizons are not stable against perturbations of null fluids and massless scalar fields;…