scholarly journals The nef cone of toroidal compactifications of ${\cal A}_4$

2004 ◽  
Vol 88 (03) ◽  
pp. 659-704 ◽  
Author(s):  
K. Hulek ◽  
G. K. Sankaran
Keyword(s):  
Toroidal Compactifications ◽  
Nef Cone

scholarly journals KLT factorization of winding string amplitudes

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Jaume Gomis ◽  
Ziqi Yan ◽  
Matthew Yu
Keyword(s):  
Scattering Amplitudes ◽  
Open String ◽  
Closed String ◽  
Open Strings ◽  
Toroidal Compactifications ◽  
Quantum Numbers ◽  
String Amplitudes

Abstract We uncover a Kawai-Lewellen-Tye (KLT)-type factorization of closed string amplitudes into open string amplitudes for closed string states carrying winding and momentum in toroidal compactifications. The winding and momentum closed string quantum numbers map respectively to the integer and fractional winding quantum numbers of open strings ending on a D-brane array localized in the compactified directions. The closed string amplitudes factorize into products of open string scattering amplitudes with the open strings ending on a D-brane configuration determined by closed string data.

scholarly journals K-RATIONAL D-BRANE CRYSTALS

2012 ◽  
Vol 27 (22) ◽  
pp. 1250112
Author(s):  
ROLF SCHIMMRIGK
Keyword(s):  
String Theory ◽  
Algebraic Number ◽  
Special Class ◽  
Building Blocks ◽  
Number Fields ◽  
Central Point ◽  
Algebraic Number Fields ◽  
Special Values ◽  
Toroidal Compactifications ◽  
Base Points

In this paper the problem of constructing space–time from string theory is addressed in the context of D-brane physics. It is suggested that the knowledge of discrete configurations of D-branes is sufficient to reconstruct the motivic building blocks of certain Calabi–Yau varieties. The collections of D-branes involved have algebraic base points, leading to the notion of K-arithmetic D-crystals for algebraic number fields K. This idea can be tested for D0-branes in the framework of toroidal compactifications via the conjectures of Birch and Swinnerton-Dyer. For the special class of D0-crystals of Heegner type these conjectures can be interpreted as formulae that relate the canonical Néron–Tate height of the base points of the D-crystals to special values of the motivic L-function at the central point. In simple cases the knowledge of the D-crystals of Heegner type suffices to uniquely determine the geometry.

scholarly journals The nef cone volume of generalized Del Pezzo surfaces

2008 ◽  
Vol 2 (2) ◽  
pp. 157-182 ◽  
Author(s):  
Ulrich Derenthal ◽  
Michael Joyce ◽  
Zachariah Teitler
Keyword(s):  
Del Pezzo Surfaces ◽  
Del Pezzo ◽  
Nef Cone

scholarly journals Stringy dyonic solutions and clifford structures

2019 ◽  
Vol 16 (09) ◽  
pp. 1950138
Author(s):  
A. Belfakir ◽  
A. belhaj ◽  
Y. El Maadi ◽  
S. E. Ennadifi ◽  
Y. Hassouni ◽  
...  
Keyword(s):  
Black Hole ◽  
Gauge Symmetry ◽  
Standard Model ◽  
Clifford Algebras ◽  
Magnetic Monopole ◽  
Toroidal Compactifications ◽  
The Standard Model ◽  
Arbitrary Dimensions ◽  
Electrically Charged ◽  
Clifford Structures

Using the toroidal compactification of string theory on [Formula: see text]-dimensional tori, [Formula: see text], we investigate dyonic objects in arbitrary dimensions. First, we present a class of dyonic black solutions formed by two different D-branes using a correspondence between toroidal cycles and objects possessing both magnetic and electric charges, belonging to [Formula: see text] dyonic gauge symmetry. This symmetry could be associated with electrically charged magnetic monopole solutions in stringy model buildings of the standard model (SM) extensions. Then, we consider in some detail such black hole classes obtained from even-dimensional toroidal compactifications, and we find that they are linked to [Formula: see text] Clifford algebras using the vee product. It is believed that this analysis could be extended to dyonic objects which can be obtained from local Calabi–Yau manifold compactifications.

scholarly journals Remarks on the nef cone on symmetric products of curves

2009 ◽  
Vol 130 (1) ◽  
pp. 113-120 ◽  
Author(s):  
F. Bastianelli
Keyword(s):  
Symmetric Products ◽  
Nef Cone

scholarly journals Nef cone of flag bundles over a curve

2014 ◽  
Vol 54 (2) ◽  
pp. 353-366 ◽  
Author(s):  
Indranil Biswas ◽  
A. J. Parameswaran
Keyword(s):  
Nef Cone

scholarly journals M-THEORY DUALITY AND BPS-EXTENDED SUPERGRAVITY

2001 ◽  
Vol 16 (05) ◽  
pp. 1002-1011 ◽  
Author(s):  
BERNARD DE WIT
Keyword(s):  
Lorentz Invariance ◽  
Space Time ◽  
Duality Group ◽  
Toroidal Compactifications ◽  
Maximal Supergravity ◽  
Bps States ◽  
M Theory

We discuss toroidal compactifications of maximal supergravity coupled to an extended configuration of BPS states which transform consistently under the U-duality group. Under certain conditions this leads to theories that live in more than eleven space-time dimensions, with maximal supersymmetry but only partial Lorentz invariance. We demonstrate certain features of this construction for the case of nine-dimensional N=2 supergravity.

scholarly journals FINITENESS OF LOG MINIMAL MODELS AND NEF CURVES ON -FOLDS IN CHARACTERISTIC

2018 ◽  
Vol 239 ◽  
pp. 76-109
Author(s):  
OMPROKASH DAS
Keyword(s):  
Projective Variety ◽  
Smooth Projective Variety ◽  
Minimal Models ◽  
Full Generality ◽  
Canonical Divisor ◽  
Arbitrary Characteristic ◽  
Finiteness Result ◽  
Effective Divisors ◽  
Cone Of Curves ◽  
Nef Cone

In this article, we prove a finiteness result on the number of log minimal models for 3-folds in $\operatorname{char}p>5$. We then use this result to prove a version of Batyrev’s conjecture on the structure of nef cone of curves on 3-folds in characteristic $p>5$. We also give a proof of the same conjecture in full generality in characteristic 0. We further verify that the duality of movable curves and pseudo-effective divisors hold in arbitrary characteristic. We then give a criterion for the pseudo-effectiveness of the canonical divisor $K_{X}$ of a smooth projective variety in arbitrary characteristic in terms of the existence of a family of rational curves on $X$.

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