335,176 research outputs found
The Theory of Quasiconformal Mappings in Higher Dimensions, I
We present a survey of the many and various elements of the modern
higher-dimensional theory of quasiconformal mappings and their wide and varied
application. It is unified (and limited) by the theme of the author's
interests. Thus we will discuss the basic theory as it developed in the 1960s
in the early work of F.W. Gehring and Yu G. Reshetnyak and subsequently explore
the connections with geometric function theory, nonlinear partial differential
equations, differential and geometric topology and dynamics as they ensued over
the following decades. We give few proofs as we try to outline the major
results of the area and current research themes. We do not strive to present
these results in maximal generality, as to achieve this considerable technical
knowledge would be necessary of the reader. We have tried to give a feel of
where the area is, what are the central ideas and problems and where are the
major current interactions with researchers in other areas. We have also added
a bit of history here and there. We have not been able to cover the many recent
advances generalising the theory to mappings of finite distortion and to
degenerate elliptic Beltrami systems which connects the theory closely with the
calculus of variations and nonlinear elasticity, nonlinear Hodge theory and
related areas, although the reader may see shadows of this aspect in parts
Gravity as a Gauge Theory of Translations
The Poincar\'e group can be interpreted as the group of isometries of a
minkowskian space. This point of view suggests to consider the group of
isometries of a given space as the suitable group to construct a gauge theory
of gravity. We extend these ideas to the case of maximally symmetric spaces to
reach a realistic theory including the presence of a cosmological constant.
Introducing the concept of "minimal tetrads" we deduce Einstein gravity in the
vacuum as a gauge theory of translations.Comment: 14 pages. LaTeX 2
The familes Lonchopteridae, Opetiidae and Pipunculidae of Malta (Diptera, Aschiza)
An account is given of the three Aschiza families of Diptera: one species of Lonchopteridae, one species of Opetiidae and four species of Pipunculidae that occur in Malta and which are all new records for this countrypeer-reviewe
Diptera Carnoidea of the Maltese Islands
An account is given of the families in the Carnoidea (Diptera: Schizophora) that have not been recorded previously from Malta. These are Braulidae, one species, Canacidae, one species, Carnidae, two species and Milichiidae, seven species.peer-reviewe
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