arXiv subjects

Sunyoung Shin

Publications and source records attributed to Sunyoung Shin.

24 records · Page 2Linked to original sources

arXiv2010

Holographic 1/Nc correction from the chiral condensate

We investigate a gravity solution containing the gravitational backreaction of the massive scalar field dual to the chiral condensate, which corresponds to $1/N_c$ correction. In general, condensation changes the vacuum structure, so the present dual geometry is appropriate to describe the chiral condensate vacuum in the gauge theory side. After constructing the dual geometry numerically and applying the hard wall model we study the effect of the $1/N_c$ correction on the lightest meson spectra, which improves the values for lightest meson masses into the observations. In addition, we investigate the chiral condensate dependence the binding energy of heavy quarkonium.

hep-th↗

arXiv2010

Hamiltonian analysis of Linearized Extension of Hořava-Lifshitz gravity

We investigate the Hamiltonian structure of linearized extended Hořava- Lifshitz gravity in a flat cosmological background following the Faddeev-Jackiw's Hamiltonian reduction formalism. The Hamiltonian structure of extended Hořava-Lifshitz gravity is similar to that of the projectable version of original Hořava-Lifshitz gravity, in which there is one primary constraint and so there are two physical degrees of freedom. We also find that extra scalar graviton mode in an inflationary background can be decoupled from the matter field in the infrared (IR) limit, but it is coupled to the matter field in a general cosmological background. But it is necessary to go beyond linear order in order to draw any conclusion of the strong coupling problem.

hep-th↗

arXiv2010

Possible evidence of non-Fermi liquid behavior from quasi-one-dimensional indium nanowires

We report possible evidence of non-Fermi liquid (NFL) observed at room temperature from the quasi one-dimensional (1D) indium (In) nanowires self-assembled on Si(111)-7$\times$7 surface. Using high-resolution electron-energy-loss spectroscopy, we have measured energy and width dispersions of a low energy intrasubband plasmon excitation in the In nanowires. We observe the energy-momentum dispersion $ω$(q) in the low q limit exactly as predicted by both NFL theory and the random-phase-approximation. The unusual non-analytic width dispersion $ζ(q) \sim q^α$ measured with an exponent $α$=1.40$\pm$0.24, however, is understood only by the NFL theory. Such an abnormal width dispersion of low energy excitations may probe the NFL feature of a non-ideal 1D interacting electron system despite the significantly suppressed spin-charge separation ($\leq$40 meV).

cond-mat.mes-hall↗

arXiv2009

Walls in supersymmetric massive nonlinear sigma model on complex quadric surface

The Bogomol'nyi-Prasad-Sommerfield (BPS) multiwall solutions are constructed in a massive Kahler nonlinear sigma model on the complex quadric surface, Q^N=SO(N+2)/[SO(N)\times SO(2)] in 3-dimensional space-time. The theory has a non-trivial scalar potential generated by the Scherk-Schwarz dimensional reduction from the massless nonlinear sigma model on Q^N in 4-dimensional space-time and it gives rise to 2[N/2+1] discrete vacua. The BPS wall solutions connecting these vacua are obtained based on the moduli matrix approach. It is also shown that the moduli space of the BPS wall solutions is the complex quadric surface Q^N.

hep-th↗

arXiv2009

Oblique DLCQ M-theory and Multiple M2-branes

We propose an oblique DLCQ as a limit to realize a theory of multiple M2-branes in M(atrix)-theory context. The limit is a combination of an infinite boosting of a space-like circle and a tuned tilting of the circle direction. We obtain a series of supergravity solutions describing various dual configurations including multiple M2-branes. For an infinite boosting along a circle wrapped obliquely around a rectangular torus, Seiberg's DLCQ limit distorts the torus modulus. In the context of supergravity, we show explicitly how this torus modulus of $\widetilde{\text M}$-theory is realized as the vacuum modulus of dual IIB-theory.

hep-th↗

arXiv2009

Quantum SUSY Algebra of $Q$-lumps in the Massive Grassmannian Sigma Model

We compute the $\mathcal{N}=2$ SUSY algebra of the massive Grassmannian sigma model in 2+1 dimensions. We first rederive the action of the model by using the Scherk-Schwarz dimensional reduction from $\mathcal{N}=1$ theory in 3+1 dimensions. Then, we perform the canonical quantization by using the Dirac method. We find that a particular choice of the operator ordering yields the quantum SUSY algebra of the $Q$-lumps with cental extension.

hep-th↗