scholarly journals Deformations of elliptic fiber bundles in positive characteristic

2013 ◽  
Vol 211 ◽  
pp. 79-108 ◽  
Author(s):  
Holger Partsch
Keyword(s):  
Deformation Theory ◽  
Positive Characteristic ◽  
Fiber Bundles ◽  
Elliptic Surfaces ◽  
Elliptic Fibrations ◽  
Elliptic Fiber

AbstractWe study the deformation theory of elliptic fiber bundles over curves in positive characteristics. As applications, we give examples of nonliftable elliptic surfaces in characteristics 2 and 3, which answer a question of Katsura and Ueno. Also, we construct a class of elliptic fibrations, whose liftability is equivalent to a conjecture of Oort concerning the liftability of automorphisms of curves. Finally, we classify deformations of bielliptic surfaces.

scholarly journals Deformations of elliptic fiber bundles in positive characteristic

2013 ◽  
Vol 211 ◽  
pp. 79-108
Author(s):  
Holger Partsch
Keyword(s):  
Deformation Theory ◽  
Positive Characteristic ◽  
Fiber Bundles ◽  
Elliptic Surfaces ◽  
Elliptic Fibrations ◽  
Elliptic Fiber

AbstractWe study the deformation theory of elliptic fiber bundles over curves in positive characteristics. As applications, we give examples of nonliftable elliptic surfaces in characteristics 2 and 3, which answer a question of Katsura and Ueno. Also, we construct a class of elliptic fibrations, whose liftability is equivalent to a conjecture of Oort concerning the liftability of automorphisms of curves. Finally, we classify deformations of bielliptic surfaces.

scholarly journals On Deformations of 1-motives

2019 ◽  
Vol 62 (1) ◽  
pp. 11-22
Author(s):  
A. Bertapelle ◽  
N. Mazzari
Keyword(s):  
Abelian Variety ◽  
Deformation Theory ◽  
Positive Characteristic ◽  
Infinitesimal Deformation ◽  
Tate Group

AbstractAccording to a well-known theorem of Serre and Tate, the infinitesimal deformation theory of an abelian variety in positive characteristic is equivalent to the infinitesimal deformation theory of its Barsotti–Tate group. We extend this result to 1-motives.

scholarly journals TOWARDS THE STANDARD MODEL SPECTRUM FROM ELLIPTIC CALABI–YAU MANIFOLDS

2004 ◽  
Vol 19 (12) ◽  
pp. 1987-2014 ◽  
Author(s):  
BJÖRN ANDREAS ◽  
GOTTFRIED CURIO ◽  
ALBRECHT KLEMM
Keyword(s):  
Standard Model ◽  
Global Section ◽  
Elliptic Surfaces ◽  
Spectral Cover ◽  
Elliptic Fiber ◽  
The Standard Model ◽  
Free Involution ◽  
Simply Connected ◽  
Rational Elliptic Surfaces ◽  
Standard Model Gauge Group

We show that it is possible to construct supersymmetric three-generation models with the Standard Model gauge group in the framework of non-simply-connected elliptically fibered Calabi–Yau threefolds, without section but with a bi-section. The fibrations on a cover Calabi–Yau threefold, where the model has six generations of SU(5) and the bundle is given via the spectral cover description, use a different description of the elliptic fiber which leads to more than one global section. We present two examples of a possible cover Calabi–Yau threefold with a free involution: one is a fiber product of rational elliptic surfaces dP9; another example is an elliptic fibration over a Hirzebruch surface. We compute the necessary amount of chiral matter by "turning on" a further parameter which is related to singularities of the fibration and the branching of the spectral cover.

scholarly journals Desingularized fiber products of semi-stable elliptic surfaces with vanishing third Betti number

2009 ◽  
Vol 145 (1) ◽  
pp. 89-111 ◽  
Author(s):  
Chad Schoen
Keyword(s):  
Betti Number ◽  
Deformation Theory ◽  
Canonical Bundle ◽  
Elliptic Surfaces

AbstractDesingularized fiber products of semi-stable elliptic surfaces withHetale3=0 are classified. Such varieties may play a role in the study of supersingular threefolds, of the deformation theory of varieties with trivial canonical bundle, and of arithmetic degenerations of rigid Calabi–Yau threefolds.

Deformations of Poisson structures on fibered manifolds and adiabatic slow–fast systems

2017 ◽  
Vol 14 (06) ◽  
pp. 1750086 ◽  
Author(s):  
Misael Avendaño-Camacho ◽  
Yury Vorobiev
Keyword(s):  
Perturbation Theory ◽  
Hamiltonian Systems ◽  
Deformation Theory ◽  
Normal Forms ◽  
Geometric Approach ◽  
Fiber Bundles ◽  
Poisson Structures ◽  
Averaging Theorem ◽  
Fibered Manifolds ◽  
Adiabatic Perturbation Theory

In the context of normal forms, we study a class of slow–fast Hamiltonian systems on general Poisson fiber bundles with symmetry. Our geometric approach is motivated by a link between the deformation theory for Poisson structures on fibered manifolds and the adiabatic perturbation theory. We present some normalization results which are based on the averaging theorem for horizontal 2-cocycles on Poisson fiber bundles.

Dupuytren's Contracture and Microvessels

1981 ◽  
Vol 39 ◽  
pp. 470-471
Author(s):  
C. W. Klscher ◽  
D. Speer
Keyword(s):  
Hypertrophic Scar ◽  
Active Form ◽  
Scar Tissue ◽  
Vascular Supply ◽  
Fiber Bundles ◽  
Dupuytren’S Contracture ◽  
Palmar Fascia ◽  
Immune Disease ◽  
Dupuytren's Contracture ◽  
Longitudinal Fiber

Dupuytren's Contracture is a nodular proliferation of the longitudinal fiber bundles of palmar fascia with its attendant contraction. The factors attributed to its etiology have included trauma, diabetes, alcoholism, arthritis, and auto-immune disease. The tissue has been observed by electron microscopy and found to contain myofibroblasts.Dupuytren's Contracture constitutes a scar, and as such, excessive collagen can be observed, along with an active form of fibroblast.Previous studies of the hypertrophic scar have led us to propose that integral in the initiation and sustenance of scar tissue is a profusion of microvascular regeneration, much of which becomes and remains occluded producing a hypoxia which stimulates fibroblast synthesis. Thus, when considering a study of Dupuytren's Contracture, we predicted finding occluded microvessels at or near the fascial scarring focus.Three cases of Dupuytren's Contracture yielded similar specimens, which were fixed in Karnovskys fluid for 2 to 20 days. Upon removal of the contracture bands care was taken to include the contiguous fatty and areolar tissue which contain the vascular supply and to identify the junctional area between old and new fascia.

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