A5082599879- Advanced Differential Geometry Research
- Relativity and Gravitational Theory
- Black Holes and Theoretical Physics
- Noncommutative and Quantum Gravity Theories
- Cosmology and Gravitation Theories
- Quantum Mechanics and Applications
- Nonlinear Waves and Solitons
- Algebraic and Geometric Analysis
- Geometric Analysis and Curvature Flows
- Mathematics and Applications
- Quantum Mechanics and Non-Hermitian Physics
- Geometry and complex manifolds
- Astrophysical Phenomena and Observations
- Quantum Electrodynamics and Casimir Effect
- Gamma-ray bursts and supernovae
- Experimental and Theoretical Physics Studies
- Solid-state spectroscopy and crystallography
- Crystallography and Radiation Phenomena
- History and Developments in Astronomy
- Morphological variations and asymmetry
- Pulsars and Gravitational Waves Research
- Quantum, superfluid, helium dynamics
- Mechanics and Biomechanics Studies
- Analytic Number Theory Research
- Mathematical Approximation and Integration
National University of Ireland
2001-2022
University College Cork
1976-2013
We present phase resolved optical spectroscopy and photometry of V4580 Sagittarii, the counterpart to accretion powered millisecond pulsar SAX J1808.4−3658, obtained during 2008 September/October outburst. Doppler tomography N iiiλ4640.64 Bowen blend emission line reveals a focused spot at location consistent with secondary star. The velocity this occurs 324 ± 15 km s−1; applying 'K-correction', we find star projected on sight be 370 40 s−1. Based existing pulse timing measurements,...
GRS 1915+105 has the largest mass function of any Galactic black hole system, although error is relatively large. Here we present spectroscopic analysis medium-resolution IR VLT archival data in K-band. We find an updated ephemeris, and report on attempts to improve by a refinement radial velocity estimate. show that spectra are significantly affected presence phase-dependent CO bandhead emission, possibly originating from accretion disc: discuss impact this efforts better constrain mass....
A unified framework for defining Lie and covariant derivatives of spinor fields is presented, which applicable without restriction on the spacetime connection. The results obtained previously by other authors are analysed compared with outcomes this new formalism.
The class of "commutative" D-operators, which was introduced in the first part this paper, is generalized to obtain "principal" class. It established that principal D-operators are expressible terms covariant differentiation and a tensor field. Necessary sufficient conditions determined for curvature operator be tensorial, scalar exist. As an application, Einstein–Maxwell theory recast new geometrical framework.
A unified framework is provided in which Lie and covariant differentiation may be considered as special cases of a new operation, called “D differentiation.” The present article develops D tensor fields, whereas the extension to spinor “D̃ differentiation,” presented companion article. concept “generalized curvature” introduced, bundle formulation obtained.
A special class of operators D-differentiation is introduced, called the "commutative" kind. It closely related to family operators, curvature which a tensor (as opposed non-linear operator), and that admitting scalar curvature. found all commutative admit curvature, but only proper subset them (which explicitly characterized) has operator tensor. also established can be expressed in terms covariant differentiation field. This generalizes well-known result about difference two sets...
The operation of D-differentiation, introduced by Hurley and Vandyck (Hurley D M 1999 submitted), briefly summarized here, is applied to the treatment semiclassical motion electrons in crystals. It shown that corresponding trajectories are remarkable geometrical curves, called euthygrammes, which generalize geodesics Riemannian manifolds.
The most general operator of D-differentiation is proved to be expressible as a combination covariant differentiation and tensor field. torsion, the curvature non-metricity an arbitrary D-operator are consequently given in terms those differentiation. scalar also obtained.
A geometrical framework for the de Broglie–Bohm quantum theory is presented, in which trajectories of an N-particle system are interpretable as integral curves a particular vector field defined on 3N-dimensional manifold [Formula: see text] constructed from physical space M. It mathematically valid even when M curved. If flat, usual recovered and automatically expressed whatever curvilinear coordinates one may wish to choose. The general construction illustrated by case free particle moving...
For pt. 1, see ibid., vol. 27, p. (1994). The framework developed in part I for defining Lie and covariant differentiation of spinors is investigated to show its compatibility with tensor calculus. special role played by conformal Killing vectors connections also determined.
By introducing the mathematical concept of orientation, significance minus sign in Faraday’s law may be made clear to students with some knowledge vector calculus. For many students, however, traditional approach treating as a relationship between positive scalars and relying on Lenz’s provide information direction induced electromotive force preferable pedagogical practice.
The axiom of uniform visibility on simply connected manifolds was introduced in [8] by Eberlein and O'Neill. Using the axiom, they were able to extend a class non-positive sectional curvature many results which known be true for case strictly negative curvature. proved very useful obtaining about geodesic flow [3], [4].
In recent years the geometry of generic submanifolds Euclidean space has been theobject much study. Thorn hinted in [7] that focal set such a submanifold couldprofitably be studied by using family distance squared functions on thesubmanifold from points ambient space. For isthe catastrophe or bifurcation this family. The key to obtaining results thelocal structure is transversality theorem Looijenga [5]; for analternative exposition see [8].