1,721,010 research outputs found
ON THE TOPOLOGICAL EQUIVALENCE OF GAUGE AND HIGGS FIELDS IN THE DYON SECTORS
No full textWe prove by topological methods methods that in the context of SU(2) gauge theory the integers labelling the homotopy classes of Yang-Mills and Higgs fields are equal for periodic instanton and dyon configurations. A similar statement is true for the group SO(3) and, in the periodic instanton case, whenever a simply connected group is broken down to an abelian subgroup. We briefly discuss how the result goes over to the canonically quantized theor
TOPOLOGY AND FRACTIONAL SPIN IN THE (2+1)-DIMENSIONAL SIGMA MODEL
No full textWe discuss the appearance of theta vacua and solitons with fractional spin in the S2-valued nonlinear sigma model in two space dimensions. We use a formulation of the sigma model in terms of Euler angles and work within the context of canonical quantization. We show that when the model is coupled to an SU(2) topologically massive theory, the theta sectors disappear and the topological mass is not quantized
HAMILTONIAN METHODS FOR NONLINEAR SIGMA-MODELS
No full textNonlinear sigma models are studied in n space dimensions with values in a coset space G/H as infinite dimensional Hamiltonian systems. An "intrinsic" formulation is discussed in terms of coordinates on G/H, an "embedded" formulation in terms of fields satisfying a constraint and a "lifted" formulation in terms of fields having values in G/H, where H is a normal subgroup of H. The coupling of the sigma model to Yang-Mills fields with structure group G is then considered, and it is shown that this system is equivalent to a massive Yang-Mills theor
Construction of the effective vertices and the gauge invariant currents in the gauged Wess-Zumino action
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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