Notes on Supersymmetry Enhancement of ABJM Theory (2009)
Kwon, O-Kab, Oh, Phillial, Sohn, Jongsu
We study the supersymmetry enhancement of ABJM theory. Starting from a ${\cal N}=2$ supersymmetric Chern-Simons matter theory with gauge group U(2)$\times$U(2) which is a truncated version of the...
Coupling between M2-branes and Form Fields (2009)
Kim, Yoonbai, Kwon, O-Kab, Nakajima, Hiroaki, Tolla, D. D.
In the context of low-energy effective theory of multiple M2-branes, we construct the interaction terms between the world-volume fields of M2-branes and the antisymmetric tensor fields of three- and...
Vortex-type Half-BPS Solitons in ABJM Theory (2009)
Kim, Chanju, Kim, Yoonbai, Kwon, O-Kab, Nakajima, Hiroaki
We study Aharony-Bergman-Jafferis-Maldacena (ABJM) theory without and with mass deformation. It is shown that maximally supersymmetry preserving, D-term, and F-term mass deformations of single mass...
Tachyon Vacuum Solution in Open String Field Theory with Constant B Field (2008)
Ishida, Akira, Kim, Chanju, Kim, Yoonbai, Kwon, O-Kab, Tolla, D. D.
We show that Schnabl's tachyon vacuum solution is an exact solution of the equation of motion of Witten's open bosonic string field theory in the background of constant antisymmetric two-form field....
Negative-Tension Branes and Tensionless 1/2 Brane in Boundary Conformal Field Theory (2008)
Ishida, Akira, Kim, Chanju, Kim, Yoonbai, Kwon, O-Kab
In the framework of boundary conformal field theory we consider a flat unstable D$p$-brane in the presence of a large constant electromagnetic field. Specifically, we study the case that the...
Lower Dimensional Branes in Boundary Conformal Field Theory (2008)
Ishida, Akira, Kim, Yoonbai, Kim, Chanju, Kwon, O-Kab
In the presence of constant background electromagnetic fields, we discuss three types of exactly marginal boundary tachyon operators for static kinks in boundary conformal field theory. Functional...
Marginally Deformed Rolling Tachyon around the Tachyon Vacuum in Open String Field Theory (2008)
We investigate the string field theory around the tachyon vacuum. A pure gauge form of the solution is constructed at the tachyon vacuum. For a special choice of the gauge function for the pure gauge...
Fluctuations around the Tachyon Vacuum in Open String Field Theory (2007)
Kwon, O-Kab, Lee, Bum-Hoon, Park, Chanyong, Sin, Sang-Jin
We consider quadratic fluctuations around the tachyon vacuum numerically in open string field theory. We work on a space ${\cal H}_N^{{\rm vac}}$ spanned by basis string states used in the Schnabl's...
Evolution of Tachyon Kink with Electric Field (2006)
Cho, Inyong, Kwon, O-Kab, Lee, Chong Oh
We investigate the decay of an inhomogeneous D1-brane wrapped on a $S^1$ with an electric field. The model that we consider consists of an array of tachyon kink and anti-kink with a constant electric...
Late Time Behaviors of an Inhomogeneous Rolling Tachyon (2006)
We study an inhomogeneous decay of an unstable D-brane in the context of Dirac-Born-Infeld~(DBI)-type effective action. We consider tachyon and electromagnetic fields with dependence of time and one...
Tachyon Kinks in Boundary String Field Theory (2006)
Kim, Chanju, Kim, Yoonbai, Kwon, O-Kab, Yee, Ho-Ung
We study tachyon kinks with and without electromagnetic fields in the context of boundary string field theory. For the case of pure tachyon only an array of kink-antikink is obtained. In the presence...
BPS D-branes from an Unstable D-brane (2005)
Kim, Chanju, Kim, Yoonbai, Kwon, Hwang-hyun, Kwon, O-Kab, Lee, Chong Oh
We search for exact tachyon kink solutions of DBI type effective action describing an unstable D-brane with worldvolume gauge field turned in both the flat and a curved background. There are various...
BPS D-branes from an Unstable D-brane in a Curved Background (2005)
Kim, Chanju, Kim, Yoonbai, Kwon, Hwang-hyun, Kwon, O-Kab
We find exact tachyon kink solutions of DBI type effective action describing an unstable D5-brane with worldvolume gauge field turned on in a curved background. The background of interest is the...
Exact Rolling Tachyon in Noncommutative Field Theory (2005)
We study the exact rolling tachyon solutions in DBI type noncommutative field theory with a constant open string metric and noncommutative parameter on an unstable D$p$-brane. Functional shapes of...
Domain Walls in Noncommutative Field Theories (2004)
Kim, Yoonbai, Kwon, O-Kab, Lee, Chong Oh
We study kinks in a wide class of noncommutative (NC) field theories. We find rich structure of the static kinks in DBI type NC tachyon action for an unstable D$p$-brane with general constant open...
Noncommutative Tachyon Kinks as D$(p-1)$-branes from Unstable D$p$-brane (2004)
Banerjee, Rabin, Kim, Yoonbai, Kwon, O-Kab
We study noncommutative (NC) field theory of a real NC tachyon and NC U(1) gauge field, describing the dynamics of an unstable D$p$-brane. For every given set of diagonal component of open string...
Unstable D-branes and String Cosmology (2004)
Kim, Chanju, Kim, Hang Bae, Kim, Yoonbai, Kwon, O-Kab, Lee, Chong Oh
Cosmological implication of rolling tachyons is reported in the context of effective field theory. With a brief review of rolling tachyons in both flat and curved spacetimes, we study the string...
Tubular D-branes in Salam-Sezgin Model (2004)
Kim, Chanju, Kim, Yoonbai, Kwon, O-Kab
We study DBI-type effective theory of an unstable D3-brane in the background manifold R^{1,1} x M_2 where M_2 is an arbitrary two-dimensional manifold. We obtain an exact tubular D2-brane solution of...
Tachyon Tube and Supertube (2003)
Kim, Chanju, Kim, Yoonbai, Kwon, O-Kab, Yi, Piljin
We search for tubular solutions in unstable D3-brane. With critical electric field E=1, solutions representing supertubes, which are supersymmetric bound states of fundamental strings, D0-branes, and...
String Fluid, Tachyon Matter, and Domain Walls (2003)
We study classical dynamics of an open string tachyon $T$ of unstable D$p$-brane coupled to the gauge field $A_\mu$. In the vacuum with vanishing potential, V=0, two fluid-like degrees of freedom,...
Tachyon Kinks on Unstable Dp-branes (2003)
Kim, Chanju, Kim, Yoonbai, Kwon, O-Kab, Lee, Chong Oh
In the context of tachyon effective theory coupled to Born-Infeld electromagnetic fields, we obtain all possible singularity-free static flat configurations of codimension one on unstable Dp-branes....
Type IIA Supergravity Excitations in Plane-Wave Background (2003)
We study the low-lying excitations of Type IIA superstring theory in a plane wave background with 24 supersymmetries. In the light-cone gauge, the superstring action has ${\cal N}=(4,4)$...
Cosmology of Rolling Tachyon (2003)
Kim, Chanju, Kim, Hang Bae, Kim, Yoonbai, Kwon, O-Kab
We study dynamics of rolling tachyon and Abelian gauge field on unstable D-branes, of which effective action is given by Born-Infeld type nonlocal action. Possible cosmological evolutions are also...
Electromagnetic String Fluid in Rolling Tachyon (2003)
Kim, Chanju, Kim, Hang Bae, Kim, Yoonbai, Kwon, O-Kab
We study Born-Infeld type effective action for unstable D3-brane system including a tachyon and an Abelian gauge field, and find the rolling tachyon with constant electric and magnetic fields as the...
Vacuum Structure and Global Strings with Conical Singularities (2002)
Kim, Yoonbai, Kwon, O-Kab, Sohn, Jongsu
Vacuum structure and global cosmic strings are analyzed in the effective theory of self-interacting O(2) scalar fields on (3+1)-manifolds with conical singularities. In the context of one-loop...
One-loop Effective Actions in Shape-invariant Scalar Backgrounds (2001)
Kim, Chanju, Kwon, O-Kab, Lee, Choonkyu
The field-theoretic one-loop effective action in a static scalar background depending nontrivially on a single spatial coordinate is related, in the proper-time formalism, to the trace of the...
Massive field contributions to the QCD vacuum tunneling amplitude (2000)
Kwon, O-Kab, Lee, Choonkyu, Min, Hyunsoo
For the one-loop contribution to the QCD vacuum tunneling amplitude by quarks of generic mass value, we make use of a calculational scheme exploiting a large mass expansion together with a small mass...
On mass dependences of the one-loop effective action in simple backgrounds (2000)
Kwon, O-Kab, Lee, Choonkyu, Min, Hyunsoo
If background fields are soft on the scale set by mass of the particle involved, a reliable approximation to the field-theoretic one-loop effective action is obtained by a systematic large mass...