(Relatively) orienting canonical coordinate charts on positroids configurations

Author(s):  
Nima Arkani-Hamed ◽  
Jacob Bourjaily ◽  
Freddy Cachazo ◽  
Alexander Goncharov ◽  
Alexander Postnikov ◽  
...  
Keyword(s):  
Author(s):  
Peter Mann

This chapter discusses canonical transformations and gauge transformations and is divided into three sections. In the first section, canonical coordinate transformations are introduced to the reader through generating functions as the extension of point transformations used in Lagrangian mechanics, with the harmonic oscillator being used as an example of a canonical transformation. In the second section, gauge theory is discussed in the canonical framework and compared to the Lagrangian case. Action-angle variables, direct conditions, symplectomorphisms, holomorphic variables, integrable systems and first integrals are examined. The third section looks at infinitesimal canonical transformations resulting from functions on phase space. Ostrogradsky equations in the canonical setting are also detailed.


2007 ◽  
Vol 45 (4) ◽  
pp. 1046-1060 ◽  
Author(s):  
Amanda K. Falcone ◽  
Mahmood R. Azimi-Sadjadi ◽  
J. Adam Kankiewicz

Author(s):  
H. Levy ◽  
W. J. Robinson

AbstractIt is shown that for an axisymmetric stationary system there exists, in vacuo, a canonical coordinate system, analogous to Weyl's canonical coordinates for the static case. Some approximate solutions of the vacuum field equations are then obtained in these canonical coordinates.In the second part of this paper, the vacuum field equations for an isolated axisymmetric stationary system are set up and approximate solutions obtained by means of a multipole expansion. The physical components of the Riemann tensor are then examined and it is found that the ‘mass term’ predominates, the ‘rotation term’ being of the next order of magnitude.


1987 ◽  
Vol 42 (4) ◽  
pp. 333-340 ◽  
Author(s):  
B. Bruhn

This paper considers various aspects of the canonical coordinate transformations in a complex phase space. The main result is given by two theorems which describe two special families of mappings between integrable Hamiltonian systems. The generating function of these transformations is determined by the entropy and a second arbitrary function which we take to be the energy function. For simple integrable systems an algebraic treatment based on the group properties of the canonical transformations is given to calculate the eigenvalue spectrum of the energy.


1971 ◽  
Vol 22 (2) ◽  
pp. 245 ◽  
Author(s):  
WT Williams ◽  
P Gillard

The complementary functions of pattern analysis and statistical analysis are discussed, with particular reference to the analysis of agricultural experiments. It is suggested that pattern analysis, in addition to its usual function of simplification of complex data, may contribute to the analysis of grazing experiments in the special case in which there is reason to suspect the existence of an external non-random environmental factor. Such a case is analysed completely; it is shown that the existence of such a factor can be established by intrinsic classification of entire liveweight sequences. The factor can then be partitioned out by principal coordinate analysis; its spatial configuration can be elucidated, and the extent of its contribution to the overall results assessed. Its optimum correlation with parallel botanical data can be established by canonical coordinate analysis. It is then possible to formulate causative hypotheses as to the nature of the factor; in the present case the most plausible hypothesis was that a small systematic change in tree density caused a progressive reduction in quantity and quality of herbage as we passed from the centre of the area to the periphery. This hypothesis could be used for further experiment and statistical test. Standard programmes for the entire analysis exist on the Control Data 3600 computer at Canberra.


Author(s):  
Duncan G. Steel

With the knowledge of the new design rules in Chapter 7, we use this new insight to find the eigenvectors for the nano-vibrator problem, and then we use the same approach to examine the quantum LC circuit. While the usual approach is to use Kirchhoff’s laws to analyze a simple circuit classically, we first see that Hamilton’s equations can in fact be used, giving the same classical result. But then, using the new design rules and the knowledge of the total energy in the circuit, we identify a canonical coordinate and a conjugate momentum that have nothing to do with real space and motion of a particle of mass m. At the same time, consistent with the Schrödinger picture, we continue to see that the time evolution of an observable such as position, x(t), or current, i(t), is not part of the solution. Given that Hamilton’s equations give the same result as Kirchhoff’s law but the quantum solution does not, reinforces the idea that the quantum description is showing features that cannot be imagined with a viewpoint based on classical (i.e. non-quantum) analysis.


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