172,059 research outputs found
Ex l. transigere, C. de transactionibus (C. 2,4,18)
No full textpro summis in utroque iure doctoralibus insigniis atque privilegiis obtinendis Michael Witten Lubecensis Ad 2. Novembris, hora locoque solitis publice discutiendas proponitLetzte Seite unbedrucktTitelvariante gemäss MommsenEnthält 16 ThesenDiss. iur. Basel, 160
The Seiberg-Witten equations on 3-manifolds with boundary
Get PDFThe Seiberg-Witten equations have proved to be quite powerful in studying smooth 4-manifolds since their landing in 1994. The corresponding Seiberg-Witten theory on
closed 3-manifolds can either be obtained by a dimension reduction from the four-dimensional theory, or by following Floer's approach. Here we investigate the theory on 3-manifolds with boundary. The solutions to the Seiberg-Witten equations are identified with critical points to the Chern-Simons-Dirac functional, regarded as a section of the U(1) bundle over the quotient B of the configuration space. An infinite tube [0, ∞) X ∑ is added to the compact manifold and the asymptotic behavior of the solutions on the cylindrical end are studied. The moduli spaces of solutions under gauge group action are finite dimensional, compact and generically smooth. For a generic perturbation h, the moduli space M_h can be related to the moduli space
M_L of the Kähler-Vortex equations on the boundary surface ∑, via a limit ing map r, which is a LagTangian immersion with respect to a canonical symplectic structure on
M_L. Moreover, for a family of admissible perturbations, the moduli spaces for the perturbed Seiberg-Witten equations are mutually Legendrian cobordant
Relative Mirror Symmetry and Ramifications of a Formula for Gromov-Witten Invariants
Get PDFFor a toric Del Pezzo surface S, a new instance of mirror symmetry, said relative, is introduced and developed. On the A-model, this relative mirror symmetry conjecture concerns genus 0 relative Gromov-Witten of maximal tangency of S. These correspond, on the B-model, to relative periods of the mirror to S. Furthermore, for S not necessarily toric, two conjectures for BPS state counts are related. It is proven that the integrality of BPS state counts of the total space of the canonical bundle on S implies the integrality for the relative BPS state counts of S. Finally, a prediction of homological mirror symmetry for the open complement is explored. The B-model prediction is calculated in all cases and matches the known A-model computation for the projective plane
A Note on the Degenerate Morse Inequalities
No full textIn this paper we give an analytic proof of the degenerate Morse inequalities in the spirit of E. Witten. The max-min methods are used to estimate the number of ‘small’ eigenvalues of Witten’s deformed Laplacian.</p
Topological Quantum Field Theory and the Geometric Langlands Correspondence
Get PDFIn the pioneering work of A. Kapustin and E. Witten, the geometric Langlands program of number theory was shown to be intimately related to duality of GL-twisted N=4 super Yang-Mills theory compactified on a Riemann surface. In this thesis, we generalize Kapustin-Witten by investigating compactification of the GL-twisted theory to three dimensions on a circle (for various values of the twisting parameter t). By considering boundary conditions in the three-dimensional description, we classify codimension-two surface operators of the GL-twisted theory, generalizing those surface operators studied by S. Gukov and E. Witten. For t=i, we propose a complete description of the 2-category of surface operators in terms of module categories, and, in addition, we determine the monoidal category of line operators which includes Wilson lines as special objects. For t=1 and t=0, we discuss surface and line operators in the abelian case.
We generalize Kapustin-Witten also by analyzing a separate twisted version of N=4, the Vafa-Witten theory. After introducing a new four-dimensional topological gauge theory, the gauged 4d A-model, we locate the Vafa-Witten theory as a special case. Compactification of the Vafa-Witten theory on a circle and on a Riemann surface is discussed. Several novel two- and three-dimensional topological gauge theories are studied throughout the thesis and in the appendices.
In work unrelated to the main thread of the thesis, we conclude by classifying codimension-one topological defects in two-dimensional sigma models with various amounts of supersymmetry.</p
Customizing digital library interfaces with Greenstone
No full textDigital libraries are organized, focused collections of information. They are focused on a particular topic or theme—and good digital libraries will articulate the principles governing what is included. They are organized to make information accessible in particular, well-defined, ways—and good ones will include a description of how the information is organized (Lesk, 1997).
The Greenstone digital library software is intended to help users construct simple collections of information very quickly. Indeed, only a few minutes of the user's time are needed to set up a collection based on a standard design and initiate the building process. Collections may be large—some comprise Gbytes of text; millions of documents. Furthermore, even larger volumes of information may be associated with a collection—typically audio, image, and video, with textual metadata. Once initiated, the mechanical process of building the collection may take from a few moments for a tiny collection to several hours for a multi-Gbyte one—perhaps even a day if it involves many different full-text indexes
Creating digital library collections with Greenstone
No full textThe Greenstone digital library software is a comprehensive system for building and distributing digital library collections. It provides a way of organizing information based on metadata and publishing it on the Internet. This paper introduces Greenstone and explains how librarians use it to create and customize digital library collections. Through an end-user interface, they add documents and metadata to collections, create new collections whose structure mirrors existing ones, and build collections and put them in place for users to view. More advanced users can design and customize new collection structures
IMPULSE-MOMENTUM RELATIONSHIPS IN GIANT SWING MOVEMENTS
Get PDFINTRODUCTION The purpose of this study was to investigate the forces applied to an instrumented top bar of the uneven parallel bars in the performance of giant swing movements in gymnastics. It was hypothesized that information derived from the time histories of horizontal and vertical forces applied to the bar would provide insight into how gymnasts perform these swinging movements. The subjects (Class I and Elite level female gymnasts) and methods for this study were the same as those used by Witten, Brown, Witten, and Wells (1996). In addition to sampling (100 Hz) the time histories of the forces of the subjects (five in highly skilled (HS) and five in less skilled (LS) groups) in their performances of the overgrip giant swing, kinematic data were recorded with a SVHS video camera. RESULTS AND CONCLUSIONS Table 1 is a summary of the horizontal and vertical impulses in the overgrip giant swing and their influences on the velocities of the subjects\u27 centers of gravity. It was determined that only Subjects 4 and 5 (both in Group HS) were able to effect a desired influence on the horizontal and vertical velocity of their center of gravity from the start to the finish of the giant swing. Performance Parameters in the Overgrip Giant Swing (impulses reported in Ns) REFERENCE Witten, W. A., Brown, E. W., Witten, C. X., Wells, R. (1996). Kinematic and kinetic analysis of the overgrip giant swing on the uneven parallel bars. Journal of Applied Biomechanics, 12,431-448
Carp (Cyprinus carpio) as an alternative model to study skeletogenesis in farmed fish species
No full textPhenotypic Variation of the Zebrafish (Danio rerio, Actinopterygii: Cyprinidae) Skeleton in Response to Rearing Density
No full textThe response of individuals to novel or altered environments is defined as "phenotypic plasticity“. Plasticity is a fundamental character of the vertebrate skeleton (1). The Skeleton is active and dynamic throughout life and capable to adapt to mechanical forces and environmental changes. Here we study how rearing density affects skeletal development in zebrafish. From 30 to 90 days post fertilisation zebrafish were reared at three different densities. High density (HD) 32 fish/L, medium density (MD) 8 fish/L and low density (LD) 2 fish/L. A connected recirculating system ensured homogenous water chemistry. At the end of the experiment, animals were whole mount stained with Alizarin red S to visualise calcified tissues. Then, the entire skeleton was analysed for 113 malformations types (modified from (2)) and vertebral body malformations were subjected to histological analyses. The animals’ average standard length decreased with increasing rearing density. The HD group had the highest variety of malformations throughout the skeleton and the highest number of malformations per malformed specimens. The HD group particularly showed malformations in the caudal region of the vertebral column, such as dislocation of neural and haemal arches, missing distal fusion of arches and malformed neural and haemal spines. Histological analyses showed a variable size of muscle segments while arches and spines align with dislocated myosepta. Vertebral centra can extend over two myosepta, the opposite of diplospondyly. Interestingly, similar malformations have been described for tbx6 mutant (fssti1) and transgenic zebrafish in which the Notch pathway was inhibited (3). The mechanisms by which rearing density induces late vertebral column malformations similar to early, mutant-related, malformations remain to be elucidated
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