4,368 research outputs found
Twistor Phase Space Dynamics and the Lorentz Force Equation
Using Lorentz force equation as an input a Hamiltonian mechanics on the
non-projective two twistor phase space TxT is formulated. Such a construction
automatically reproduces dynamics of the intrinsic classical relativistic spin.
The charge appears as a dynamical variable. It is also shown that if the
classical relativistic spin function on TxT vanishes, the natural conformally
invariant symplectic structure on TxT reduces to the natural symplectic
structure on the cotangent bundle of the Kaluza-Klein space.Comment: LaTeX file, 20 page
Barriers to Work Place Advancement: the Experience of the White Female Work Force
Glass Ceiling ReportGlassCeilingBackground17WhiteFemaleWorkForce.pdf: 8903 downloads, before Oct. 1, 2020
Relativistic Spinor Dynamics Inducing the Extended Lorentz-Force-Like Equation
The special relativistic dynamical equation of the Lorentz force type can be
regarded as a consequence of a succession of space-time dependent infinitesimal
Lorentz transformations as shown by one of us \cite{buitrago} and discussed in
the introduction below. Such an insight indicates that the Lorentz-force-like
equation has an extremely fundamental meaning in physics. In this paper we
therefore present a set of dynamical Weyl spinor equations {\em inducing} the
extended Lorentz-force-like equation in the Minowski space-time. The term
extended refers to the dynamics of some additional degrees of freedom that may
be associated with the classical spin namely with the dynamics of three
space-like mutually orthogonal four-vectors, all of them orthogonal to the
linear four-momentum of the object under consideration.Comment: 15 page
Regulation of Murine Class I Genes by Interferons is Controlled by Regions Located Both 5' and 3' to the Transcription Initiation Site
Interferons regulate the expression of a large number of mammalian genes, including the major histocompatibility antigen genes. To investigate the mechanisms involved in interferon action, we have analyzed the ability of murine H-2Ld and H-2Dd DNA sequences to control the responses to interferon. The results indicate that interferon regulation of class I gene expression is complex and involves at least two mechanisms that are dependent on class I sequences located upstream and downstream to the transcription initiation site. In transfected mouse L cells, both of these regions are required for full enhancement of class I gene expression, with the major portion of the response controlled by the sequences located 3' to the transcription initiation site. The fine-mapping analysis of the 5' region-encoded response also suggests that recombinant alpha and gamma interferons may exert their effects on class I gene expression by using different cis-acting regulatory sequences
Directly Interacting Massless Particles - a Twistor Approach
Twistor phase spaces are used to provide a general description of the
dynamics of a finite number of directly interacting massless spinning particles
forming a closed relativistic massive and spinning system with an internal
structure. A Poincare invariant canonical quantization of the so obtained
twistor phase space dynamics is performed.Comment: LaTeX, approx. 16 pages; to appear in Journal of Mathematical
Physics, March or April 1996 issu
Twistors, special relativity, conformal symmetry and minimal coupling - a review
An approach to special relativistic dynamics using the language of spinors
and twistors is presented. Exploiting the natural conformally invariant
symplectic structure of the twistor space, a model is constructed which
describes a relativistic massive, spinning and charged particle, minimally
coupled to an external electro-magnetic field. On the two-twistor phase space
the relativistic Hamiltonian dynamics is generated by a Poincare scalar
function obtained from the classical limit (appropriately defined by us) of the
second order, to an external electro-magnetic field minimally coupled, Dirac
operator. In the so defined relativistic classical limit there are no Grassman
variables. Besides, the arising equation that describes dynamics of the
relativistic spin differs significantly from the so called Thomas Bergman
Michel Telegdi equation.Comment: 39 pages, no figures, few erronous statements (not affecting anything
else in the papper) on page 23 delete
Analysis of success in beginning reading in relation to knowledge of letter names, experiential background and school adjustment.
Thesis (Ed.M.)--Boston Universit
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