arXiv subjects

Hoil Kim

Publications and source records attributed to Hoil Kim.

24 records · Page 2Linked to original sources

arXiv2002

N-Point Deformation of Algebraic K3 Surfaces

We consider N-point deformation of algebraic K3 surfaces. First, we construct two-point deformation of algebraic K3 surfaces by considering algebraic deformation of a pair of commutative algebraic K3 surfaces. In this case, the moduli space of the noncommutative deformations is of dimension 19, the same as the moduli dimension of the complex deformations of commutative algebraic K3 surfaces. Then, we extend this method to the N-point case. In the N-point case, the dimension of deformation moduli space becomes 19N(N-1)/2.

hep-th↗

arXiv2001

Matrix Theory Compactification on Noncommutative $T^4/Z_2$

In this paper, we construct gauge bundles on a noncommutative toroidal orbifold $T^4_θ/Z_2$. First, we explicitly construct a bundle with constant curvature connections on a noncommutative $T^4_θ$ following Rieffel's method. Then, applying the appropriate quotient conditions for its $Z_2$ orbifold, we find a Connes-Douglas-Schwarz type solution of matrix theory compactified on $T^4_θ/Z_2$. When we consider two copies of a bundle on $T^4_θ$ invariant under the $Z_2$ action, the resulting Higgs branch moduli space of equivariant constant curvature connections becomes an ordinary toroidal orbifold $T^4/Z_2$.

hep-th↗

arXiv2000

Twisted Bundles on Noncommutative $T^4$ and D-brane Bound States

We construct twisted quantum bundles and adjoint sections on noncommutative $T^4$, and investigate relevant D-brane bound states with non-Abelian backgrounds. We also show that the noncommutative $T^4$ with non-Abelian backgrounds exhibits SO$(4,4|Z)$ duality and via this duality we get a Morita equivalent $T^4$ on which only D0-branes exist. For a reducible non-Abelian background, the moduli space of D-brane bound states in Type II string theory takes the form $\prod_a (T^4)^{q_a}/S_{q_a}$.

hep-th↗

arXiv1999

N=8 SCFT and M Theory on AdS_4 x RP^7

We study M theory on $AdS_4 \times \RP^7$ corresponding to 3 dimensional ${\cal N}=8$ superconformal field theory which is the strong coupling limit of 3 dimensional super Yang-Mills theory. For SU(N) theory, a wrapped M5 brane on $\RP^5$ can be interpreted as baryon vertex. For $SO(N)/Sp(2N)$ theory, by using the property of (co-)homology of $\RP^7$, we classify various wrapping branes and consider domain walls and the baryon vertex.

hep-th↗

arXiv1999

Branes at $\C^4/\Ga$ Singularity from Toric Geometry

We study toric singularities of the form of $\C^4/\Ga$ for finite abelian groups $\Ga \subset SU(4)$. In particular, we consider the simplest case $\Ga=\Z_2 \times \Z_2 \times \Z_2$ and find explicitly charge matrices for partial resolutions of this orbifold by extending the method by Morrison and Plesser. We obtain three kinds of algebraic equations, $z_1 z_2 z_3 z_4=z_5^2, z_1 z_2 z_3=z_4^2 z_5 $ and $z_1 z_2 z_5 = z_3 z_4$ where $z_i$'s parametrize $\C^5$. When we put $N$ D1 branes at this singularity, it is known that the field theory on the worldvolume of $N$ D1 branes is T-dual to $2 \times 2 \times 2 $ brane cub model. We analyze geometric interpretation for field theory parameters and moduli space.

hep-th↗

arXiv1998

SO(2N) (0,2) SCFT and M Theory on $AdS_7 \times {RP}^4$

We study M theory on $AdS_7 \times \RP^4$ corresponding to 6 dimensional SO(2N) $(0, 2)$ superconformal field theory on a circle which becomes 5 dimensional super Yang-Mills theory at low energies. For SU(N) (0,2) theory, a wrapped D4 brane on $§^4$ which is connected to a D4 brane on the boundary of $AdS_7$ by N fundamental strings can be interpreted as baryon vertex. For SO(2N) (0,2) theory, by using the property of homology of $\RP^4$, we classify various wrapping branes. Then we consider particles, strings, twobranes, domain walls and the baryon vertex in Type IIA string theory.

hep-th↗