scholarly journals TWISTED SYMMETRIES AND INTEGRABLE SYSTEMS

2009 ◽  
Vol 06 (08) ◽  
pp. 1305-1321 ◽  
Author(s):  
GIUSEPPE GAETA ◽  
GIAMPAOLO CICOGNA

Symmetry properties are at the basis of integrability. In recent years, it appeared that so-called twisted symmetries are as effective as standard symmetries in many respects (integrating ODEs, finding special solutions to PDEs). Here we discuss how twisted symmetries can be used to detect integrability of Lagrangian systems which are not integrable via standard symmetries.

Author(s):  
Zh. R. Myrzakulova ◽  
K. R. Yesmakhanova ◽  
Zh. S. Zhubayeva

Integrable systems play an important role in modern mathematics, theoretical and mathematical physics. The display of integrable equations with exact solutions and some special solutions can provide important guarantees for the analysis of its various properties. The Hunter-Saxton equation belongs to the family of integrable systems. The extensive and interesting mathematical theory, underlying the Hunter-Saxton equation, creates active mathematical and physical research. The Hunter-Saxton equation (HSE) is a high-frequency limit of the famous Camassa-Holm equation. The physical interpretation of HSE is the propagation of weakly nonlinear orientation waves in a massive nematic liquid crystal director field. In this paper, we propose a matrix form of the Lax representation for HSE in 𝑠𝑢ሺ𝑛 ൅ 1ሻ/𝑠ሺ𝑢ሺ1ሻ ⊕ 𝑢ሺ𝑛ሻሻ - symmetric space for the case 𝑛 ൌ 2. Lax pairs, introduced in 1968 by Peter Lax, are a tool for finding conserved quantities of integrable evolutionary differential equations. The Lax representation expands the possibilities of the equation we are considering. For example, in this paper, we will use the matrix Lax representation for the HSE to establish the gauge equivalence of this equation with the generalized Heisenberg ferromagnet equation (GHFE). The famous Heisenberg Ferromagnet Equation (HFE) is one of the classical equations integrable through the inverse scattering transform. In this paper, we will consider its generalization. Andalso the connection between the decisions of the HSE and the GHFE will be presented.


Author(s):  
B. Carragher ◽  
M. Whittaker

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.


Physica ◽  
1952 ◽  
Vol 18 (2) ◽  
pp. 1017-1019 ◽  
Author(s):  
D PURSEY

1987 ◽  
Vol 48 (11) ◽  
pp. 2023-2026 ◽  
Author(s):  
T. Simonson ◽  
F. Ddnoyer ◽  
R. Currat

AIAA Journal ◽  
2002 ◽  
Vol 40 ◽  
pp. 579-582 ◽  
Author(s):  
R. Mittal ◽  
J. Wilson ◽  
F. M. Najjar
Keyword(s):  

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