3,096 research outputs found
Oribatid mites in the Lake Mätäjärvi
Three different periods can be separated in the development of the Lake Mätäjärvi. The first period is a sea phase. At that time the research area was a bay of the sea and the living conditions for the mites were impossible. In the second phase the lake had turned into some kind of waterside or swampy meadow with a high number of oribatid species and individuals. Human activities in the lake and in its environment make it difficult to interpret the biotope exactly. The low numbers of species and individuals as well as the appearance of certain compost species in the soil in the third phase indicate that the Lake Mätäjärvi is characterized by compost-like soil
The Development of the Constitution of the United States to 1789
Immediately after the discovery of America by Columbus, King Henry VII of England sent John Cabot out in 1496 to discover regions then unknown to Christian people and take possession of them in the name of the English king. Cabot made two voyages , and by 1498 had sailed along the east coast of what is now the United States and claimed it for England. The European sovereigns by tacit agreement rested their claims upon priority of discovery. Besides this agreement the British de good their claims by sword and by treaty, so that ultimately the title to all the land embraced in the original thirteen states was vested the British crown
On chiral symmetry breaking by external magnetic fields in QED
A recent result of Gusynin, Miransky and Shovkovy concerning chiral symmetry
breaking by a constant external magnetic field in parity-invariant
three-dimensional QED is generalised to the case of inhomogeneous fields by
relating the phenomenon to the zero modes of the Dirac equation. Virtual photon
radiative corrections and four-dimensional QED are briefly discussed.Comment: 10 page Revtex file. Minor corrections, mainly in the discussion
leading upto Eqs.(10,11) and the references. Version to be publishe
Fixed Charge Ensembles and Parity Breaking Terms
Recently derived results for the exact induced parity-breaking term in 2+1
dimensions at finite temperature are shown to be relevant to the determination
of the free energy for fixed-charge ensembles. The partition functions for
fixed total charge corresponding to massive fermions in the presence of Abelian
and non-Abelian magnetic fields are discussed. We show that the presence of the
induced Chern-Simons term manifests itself in that the free energy depends
strongly on the relation between the external magnetic flux and the value of
the fixed charge.Comment: 10 pages, Revte
Gap equation in scalar field theory at finite temperature
We investigate the two-loop gap equation for the thermal mass of hot massless
theory and find that the gap equation itself has a non-zero finite
imaginary part. This indicates that it is not possible to find the real thermal
mass as a solution of the gap equation beyond order in perturbation
theory. We have solved the gap equation and obtain the real and the imaginary
part of the thermal mass which are correct up to order in perturbation
theory.Comment: 13 pages, Latex with axodraw, Minor corrections, Appendix adde
Quantum Field Theory and Differential Geometry
We introduce the historical development and physical idea behind topological
Yang-Mills theory and explain how a physical framework describing subatomic
physics can be used as a tool to study differential geometry. Further, we
emphasize that this phenomenon demonstrates that the interrelation between
physics and mathematics have come into a new stage.Comment: 29 pages, enlarged version, some typewritten mistakes have been
corrected, the geometric descrition to BRST symmetry, the chain of descent
equations and its application in TYM as well as an introduction to R-symmetry
have been added, as required by mathematicia
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