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Pragmatic 2010
Get PDFThe twelfth edition of the PRAGMATIC Summer School took place in Catania between August 30 – September 17, 2010. The lecturers were Prof. Paltin Ionescu (University of Bucharest) and Prof. Jarosław Antoni Wiśniewski (University of Warsaw), assisted by Dr. José Carlos Sierra (ICMAT Madrid) and Dr. Luis Eduardo Solá-Conde (URJC Madrid). The school was attended by eighteen students coming from Italy, Iran, Republic of Korea, Poland, Romania and Spain.</p
A remark on boundedness of manifolds embedded with small codimension
No full textFor embedded projective manifolds of small codimension we give an explicit bound for their degree, depending on the Castelnuovo–Mumford regularity of their structure sheaf. As an application, we obtain bounds for the degree of such manifolds whose structure sheaf is arithmetically Cohen–Macaulay (in a weak sense) and whose canonical map is not birational
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
On dual defective manifolds
No full textAn embedded manifold is dual defective if its dual variety is not a hypersurface. Using the geometry of the variety of lines through a general point, we characterize scrolls among dual defective manifolds. This leads to an optimal bound for the dual defect, which improves results due to Ein. We also discuss our conjecture that every dual defective manifold with cyclic Picard group should be secant defective, of a very special type, namely a local quadratic entry locus variety
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