scholarly journals BRANE SUPERPOTENTIAL AND LOCAL CALABI–YAU MANIFOLDS

2008 ◽  
Vol 23 (14n15) ◽  
pp. 2187-2189 ◽  
Author(s):  
ANTONIO RICCO
Keyword(s):  
Type Ii ◽  
Closed Expression ◽  
Complex Submanifolds ◽  
Local Space ◽  
Tubular Neighborhoods ◽  
Holomorphic Projection ◽  
Calabi Yau Manifolds

We briefly report on some recent progresses in the computation of B-brane superpotentials for Type II strings compactified on Calabi–Yau manifolds, obtained by using a paramatrization of tubular neighborhoods of complex submanifolds, also known as local spaces. In particular, we propose a closed expression for the superpotential of a brane on a genus-g curve in a Calabi–Yau threefold for the cases in which there exists a holomorphic projection from the local space around the curve to the curve itself.

scholarly journals Type II string theory on Calabi-Yau manifolds with torsion and non-Abelian discrete gauge symmetries

2017 ◽  
Vol 2017 (7) ◽  
Author(s):  
Volker Braun ◽  
Mirjam Cvetič ◽  
Ron Donagi ◽  
Maximilian Poretschkin
Keyword(s):  
String Theory ◽  
Type Ii ◽  
Gauge Symmetries ◽  
Calabi Yau Manifolds

scholarly journals EXTENDING MIRROR CONJECTURE TO CALABI–YAU WITH BUNDLES

1999 ◽  
Vol 01 (01) ◽  
pp. 65-70 ◽  
Author(s):  
CUMRUN VAFA
Keyword(s):  
Riemann Surfaces ◽  
Hodge Structure ◽  
Stable Bundle ◽  
Type Ii ◽  
Holomorphic Maps ◽  
Variation Of Hodge Structure ◽  
Mirror Side ◽  
Calabi Yau Manifolds

We define the notion of mirror of a Calabi–Yau manifold with a stable bundle in the context of type II strings in terms of supersymmetric cycles on the mirror. This allows us to relate the variation of Hodge structure for cohomologies arising from the bundle to the counting of holomorphic maps of Riemann surfaces with boundary on the mirror side. Moreover it opens up the possibility of studying bundles on Calabi–Yau manifolds in terms of supersymmetric cycles on the mirror.

Heterotic and Type II Superstrings Compactified on Calabi-Yau Manifolds

1991 ◽  
pp. 155-179
Author(s):  
S. Ferrara
Keyword(s):  
Type Ii ◽  
Calabi Yau Manifolds

scholarly journals Evaluation of Periods via Fibrations in Seiberg–Witten Theories and in Type-II String

1997 ◽  
Vol 12 (37) ◽  
pp. 2847-2858 ◽  
Author(s):  
Hisao Suzuki
Keyword(s):  
Gauge Symmetry ◽  
Simple Form ◽  
Dual Pair ◽  
K3 Surface ◽  
Type Ii ◽  
Witten Theory ◽  
Classical Fields ◽  
Two Parameter ◽  
Calabi Yau Manifolds

We show how the periods can be evaluated in Seiberg–Witten theories and in K3-fibered Calabi–Yau manifolds by using fibrations of the theories. In the Seiberg–Witten theories, it is shown that the dual pair of fields can be constructed from the classical fields in a simple form. As for Calabi–Yau manifolds which are fibrations of K3 surface, we obtain the solutions of the Picard–Fuchs equations from the periods of K3 surface. By utilizing the expression of periods for two-parameter models of type-II string, we derive the solutions of the Picard–Fuchs equations around the points of enhanced gauge symmetry and show a simple connection to the SU(2) Seiberg–Witten theory.

scholarly journals Type II/F-theory superpotentials and Ooguri–Vafa invariants of compact Calabi–Yau threefolds with three deformations

2014 ◽  
Vol 29 (13) ◽  
pp. 1450062 ◽  
Author(s):  
Feng-Jun Xu ◽  
Fu-Zhong Yang
Keyword(s):  
Mirror Symmetry ◽  
Type Ii ◽  
Calabi Yau Manifolds ◽  
Model Expansion

We calculate the D-brane superpotentials for two Calabi–Yau manifolds with three deformations by the generalized hypergeometric GKZ systems, which give rise to the flux superpotentials 𝒲 GVW of the dual F-theory compactification on the relevant Calabi–Yau fourfolds in the weak decoupling limit. We also compute the Ooguri–Vafa invariants from A-model expansion with mirror symmetry, which are related to the open Gromov–Witten invariants.

Type II Solar Radio Bursts over Solar Cycle 21

1994 ◽  
Vol 144 ◽  
pp. 283-284
Author(s):  
G. Maris ◽  
E. Tifrea
Keyword(s):  
Solar Radio ◽  
Interplanetary Space ◽  
Impulsive Phase ◽  
Radio Bursts ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Strong Energy ◽  
Mass Ejection ◽  
Geophysical Effect ◽  
Radio Event

The type II solar radio bursts produced by a shock wave passing through the solar corona are one of the most frequently studied solar activity phenomena. The scientific interest in this type of phenomenon is due to the fact that the presence of this radio event in a solar flare is an almost certain indicator of a future geophysical effect. The origin of the shock waves which produce these bursts is not at all simple; besides the shocks which are generated as a result of a strong energy release during the impulsive phase of a flare, there are also the shocks generated by a coronal mass ejection or the shocks which appear in the interplanetary space due to the supplementary acceleration of the solar particles.

Heat-Etching with a Bullivant Type II Simple Freeze-Cleave Device

1970 ◽  
Vol 28 ◽  
pp. 106-107 ◽  
Author(s):  
Ronald S. Weinstein ◽  
N. Scott McNutt
Keyword(s):  
New Zealand ◽  
General Hospital ◽  
Massachusetts General Hospital ◽  
Type I ◽  
Type Ii ◽  
Collaborative Effort ◽  
Temperature And Pressure ◽  
The University

The Type I simple cold block device was described by Bullivant and Ames in 1966 and represented the product of the first successful effort to simplify the equipment required to do sophisticated freeze-cleave techniques. Bullivant, Weinstein and Someda described the Type II device which is a modification of the Type I device and was developed as a collaborative effort at the Massachusetts General Hospital and the University of Auckland, New Zealand. The modifications reduced specimen contamination and provided controlled specimen warming for heat-etching of fracture faces. We have now tested the Mass. General Hospital version of the Type II device (called the “Type II-MGH device”) on a wide variety of biological specimens and have established temperature and pressure curves for routine heat-etching with the device.

Ultrastructure of pulmonary microvasculature in acute endotoxemia

1978 ◽  
Vol 36 (2) ◽  
pp. 470-471
Author(s):  
R. G. Gerrity ◽  
M. Richardson
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Alveolar Epithelium ◽  
Endothelial Damage ◽  
Capillary Endothelium ◽  
Type Ii Cells ◽  
Type Ii ◽  
Interstitial Edema ◽  
Pulmonary Capillaries ◽  
Lung Ultrastructure ◽  
Fibrin Thrombi

Dogs were injected intravenously with E_. coli endotoxin (2 mg/kg), and lung samples were taken at 15 min., 1 hr. and 24 hrs. At 15 min., occlusion of pulmonary capillaries by degranulating platelets and polymorphonuclear leukocytes (PML) was evident (Fig. 1). Capillary endothelium was intact but endothelial damage in small arteries and arterioles, accompanied by intraalveolar hemorrhage, was frequent (Fig. 2). Sloughing of the surfactant layer from alveolar epithelium was evident (Fig. 1). At 1 hr., platelet-PML plugs were no longer seen in capillaries, the endothelium of which was often vacuolated (Fig. 3). Interstitial edema and destruction of alveolar epithelium were seen, and type II cells had discharged their granules into the alveoli (Fig. 4). At 24 hr. phagocytic PML's were frequent in peripheral alveoli, while centrally, alveoli and vessels were packed with fibrin thrombi and PML's (Fig. 5). In similar dogs rendered thrombocytopenic with anti-platelet serum, lung ultrastructure was similar to that of controls, although PML's were more frequently seen in capillaries in the former (Fig. 6).

Mitochondria microcrystals deposition in some inherited diseases of lipid metabolism.

1978 ◽  
Vol 36 (2) ◽  
pp. 256-257
Author(s):  
S. Laoussadi ◽  
A. Kahan ◽  
G. Aubouy ◽  
F. Delbarre
Keyword(s):  
Synovial Tissue ◽  
Storage Disease ◽  
Metabolic Diseases ◽  
Uranyl Acetate ◽  
List Type ◽  
Type Ii ◽  
Type Number ◽  
Lipid Storage Disease ◽  
Thin Sections ◽  
Mean Size

Several patients with Fabry's, Gaucher's diseases and hyperlipoproteinemia type II and with arthropatic manifestations were observed.As no histological explanation for these symptoms was available,an ultrastructural study of synovial tissue was done to establish an anatomoclinical relation.Material and Methods :synovial membrane samples were obtained by needle biopsies of the knee from three patients with arthropatic manifestations of each disease.They were fixed in 5% glutaraldehyde, postfixed in 1% osmium tetraoxyde and embedded in Epon 812. Thin sections coloured by uranyl acetate and lead citrate were observed with an Elmiskop I Siemens electron microscope.Two important phenomena were observed in synovial tissue:Specific patterns of each lipid storage disease,which are now well known.In all the three metabolic diseases, hydroxyapatite-like crystals were found. They are characterized by their intramitochondrial localization, without any relation with cristae,an anarchic disposition and a mean size of 550 A.Crystals may be found also free in the cytoplasm of synoviocytes Some micrographs suggest an evolution in four steps :a. mitochondria with only a few microcrystalsb. mitochondria stuffed with these structuresc. disruption of mitochondria membranesd. microcrystals appear free in the cytoplasm

Labelling of non-A, non-B hepatitis infected chimpanzee hepatocytes with nuclease-gold conjugates

1984 ◽  
Vol 42 ◽  
pp. 250-251
Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson
Keyword(s):  
Endoplasmic Reticulum ◽  
Experimental Infection ◽  
Uranyl Acetate ◽  
Type I ◽  
Cellular Injury ◽  
Type Ii ◽  
Tubular Structures ◽  
Type Iii ◽  
Type Iv ◽  
Infected Chimpanzee

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.

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