Singularity-free cosmological models

Karaca, Koray


Singularity analysis of spherical Kadomtsev-Petviashvili equation
Karasu, Emine Ayşe (Physical Society of Japan, 2005-02-01)
The (2 + 1)-dimensional spherical Kadomtsev-Petviashvili (SKP) equation of J.-K. Xue [Phys. Lett. A 314 (2003) 479] fails the Painleve test for integrability at the highest resonance, where a nontrivial compatibility condition for recursion relations appears. This compatibility condition, however, is sufficiently weak and thus allows the SKP equation to possess an integrable (1 + 1)-dimensional reduction, which is found by the method of truncated singular expansion.
Singularity versus splitting theorems for stably causal spacetimes
GarciaRio, E; Kupeli, DN (Springer Science and Business Media LLC, 1996-08-01)
Splitting theorems for stable causal spacetimes admitting certain metric related reference frames are obtained in connection to timelike geodesic incompletenes.
Singularity robust balancing of parallel manipulators following inconsistent trajectories
Ozdemir, Mustafa (2016-09-01)
When compared to serial manipulators, parallel manipulators have small workspaces mainly due to their closed-loop structure. As opposed to type I singularities (or inverse kinematic singularities) that are generally encountered at the workspace boundaries, type II singularities characteristically arise within the workspace, and around them, the inverse dynamic solution becomes unbounded. Hence, a desired trajectory passing through a type II singular position cannot be achieved by the manipulator, and its us...
Singularity robust inverse dynamics of planar 2-RPR parallel manipulators
Ider, SK (SAGE Publications, 2004-07-01)
In planar parallel robots, limitations occur in the functional workspace because of interference of the legs with each other and because of drive singularities where the actuators lose control of the moving platform and the actuator forces grow without bounds. A 2-RPR (revolute, prismatic, revolute joints) planar parallel manipulator with two legs that minimizes the interference of the mechanical components is considered. Avoidance of the drive singularities is in general not desirable since it reduces the ...
Singularity Cancellation for Accurate MoM Analysis of Periodic Planar Structures in Layered Media
Adanir, Suleyman; Alatan, Lale (Institute of Electrical and Electronics Engineers (IEEE), 2020-08-01)
One of the singularity cancellation schemes proposed in the literature is applied to calculate singular integrals arising in the method of moments (MoM) analysis of 2-D periodic planar structures in multilayered media. Discrete complex image method is utilized for the accurate approximation of Green's function which also makes possible the application of the Ewald transformation for the efficient computation of the series associated with the periodic structure. This approximation and transformation modifies...
Citation Formats
K. Karaca, “Singularity-free cosmological models,” Middle East Technical University, 2000.