Algebraic Classification of Field Equations

2012 ◽  
pp. 465-536
Author(s):  
Anadijiban Das ◽  
Andrew DeBenedictis
2021 ◽  
Author(s):  
◽  
Aaron Armour

<p><b>The algebraic and geometric classification of k-algbras, of dimension fouror less, was started by Gabriel in “Finite representation type is open” [12].</b></p> <p>Several years later Mazzola continued in this direction with his paper “Thealgebraic and geometric classification of associative algebras of dimensionfive” [21]. The problem we attempt in this thesis, is to extend the resultsof Gabriel to the setting of super (or Z2-graded) algebras — our main effortsbeing devoted to the case of superalgebras of dimension four. Wegive an algebraic classification for superalgebras of dimension four withnon-trivial Z2-grading. By combining these results with Gabriel’s we obtaina complete algebraic classification of four dimensional superalgebras.</p> <p>This completes the classification of four dimensional Yetter-Drinfeld modulealgebras over Sweedler’s Hopf algebra H4 given by Chen and Zhangin “Four dimensional Yetter-Drinfeld module algebras over H4” [9]. Thegeometric classification problem leads us to define a new variety, Salgn —the variety of n-dimensional superalgebras—and study some of its properties.</p> <p>The geometry of Salgn is influenced by the geometry of the varietyAlgn yet it is also more complicated, an important difference being thatSalgn is disconnected. While we make significant progress on the geometricclassification of four dimensional superalgebras, it is not complete. Wediscover twenty irreducible components of Salg4 — however there couldbe up to two further irreducible components.</p>


Author(s):  
Andrzej Krasiński ◽  
George F. R. Ellis ◽  
Malcolm A. H. MacCallum

2019 ◽  
Vol 19 (11) ◽  
pp. 2050220 ◽  
Author(s):  
Ivan Kaygorodov ◽  
Isamiddin Rakhimov ◽  
Sh. K. Said Husain

In this paper, we give a complete algebraic classification of [Formula: see text]-dimensional complex nilpotent associative commutative algebras.


Author(s):  
Ivan Kaygorodov ◽  
Mykola Khrypchenko

2006 ◽  
Vol 38 (3) ◽  
pp. 445-461 ◽  
Author(s):  
A. Coley ◽  
N. Pelavas

Symmetry ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 453 ◽  
Author(s):  
Manuel Hohmann

We provide a comprehensive overview of metric-affine geometries with spherical symmetry, which may be used in order to solve the field equations for generic gravity theories which employ these geometries as their field variables. We discuss the most general class of such geometries, which we display both in the metric-Palatini formulation and in the tetrad/spin connection formulation, and show its characteristic properties: torsion, curvature and nonmetricity. We then use these properties to derive a classification of all possible subclasses of spherically symmetric metric-affine geometries, depending on which of the aforementioned quantities are vanishing or non-vanishing. We discuss both the cases of the pure rotation group SO ( 3 ) , which has been previously studied in the literature, and extend these previous results to the full orthogonal group O ( 3 ) , which also includes reflections. As an example for a potential physical application of the results we present here, we study circular orbits arising from autoparallel motion. Finally, we mention how these results can be extended to cosmological symmetry.


1979 ◽  
Vol 31 (2) ◽  
pp. 207-219
Author(s):  
R. E. Stong

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