@article{BrungsGraeter2017, author = {Brungs, Hans H. and Gr{\"a}ter, Joachim}, title = {On central extensions of SL(2, F) admitting left-orderings}, series = {Journal of Algebra}, volume = {486}, journal = {Journal of Algebra}, publisher = {Elsevier}, address = {San Diego}, issn = {0021-8693}, doi = {10.1016/j.jalgebra.2017.05.025}, pages = {288 -- 327}, year = {2017}, abstract = {For an arbitrary euclidean field F we introduce a central extension (G(F), Phi) of SL(2, F) admitting a left-ordering and study its algebraic properties. The elements of G(F) are order preserving bijections of the convex hull of Q in F. If F = R then G(F) is isomorphic to the classical universal covering group of the Lie group SL(2, R). Among other results we show that G(F) is a perfect group which possesses a rank 1 cone of exceptional type. We also prove that its centre is an infinite cyclic group and investigate its normal subgroups.}, language = {en} }