16,562 research outputs found
Adaptive dynamic path re-planning RRT algorithms with game theory for UAVs
The main aim of this paper is to describe an adaptive re-planning algorithm based on a RRT and Game Theory to produce an efficient collision free obstacle adaptive Mission Path Planner for Search and Rescue (SAR) missions. This will provide UAV autopilots and flight computers with the capability to autonomously avoid static obstacles and No Fly Zones (NFZs) through dynamic adaptive path replanning. The methods and algorithms produce optimal collision free paths and can be integrated on a decision aid tool and UAV autopilots
Can gravitation accelerate neutrinos?
The Lagrangian equations of motion for massive spinning test particles (tops)
moving on a gravitational background using General Relativity are presented.
The paths followed by tops are nongeodesic. An exact solution for the motion of
tops on a Schwarzschild background which allows for superluminal propagation of
tops is studied. It is shown that the solution becomes relevant for particles
with small masses, such as neutrinos. This general result is used to calculate
the necessary condition to produce superluminal motion in part of the
trajectory of a small mass particle in a weak gravitational field. The
condition for superluminal motion establishes a relation between the mass,
energy and total angular momentum of the particle.Comment: 7 pages, accepted in Class. Quantum Gra
Do electromagnetic waves always propagate along null geodesics?
We find exact solutions to Maxwell equations written in terms of four-vector
potentials in non--rotating, as well as in G\"odel and Kerr spacetimes. We show
that Maxwell equations can be reduced to two uncoupled second-order
differential equations for combinations of the components of the four-vector
potential. Exact electromagnetic waves solutions are written on given
gravitational field backgrounds where they evolve. We find that in
non--rotating spherical symmetric spacetimes, electromagnetic waves travel
along null geodesics. However, electromagnetic waves on G\"odel and Kerr
spacetimes do not exhibit that behavior.Comment: Accepted in Classical and Quantum Gravit
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