arXiv subjects

Yu-tin Huang

Publications and source records attributed to Yu-tin Huang.

95 records · Page 6Linked to original sources

arXiv2008

Worldgraph Approach to Yang-Mills Amplitudes from N=2 Spinning Particle

By coupling the N=2 spinning particle to background vector fields, we construct Yang-Mills amplitudes for trees and one loop. The vertex operators are derived through coupling the BRST charge; therefore background gauge invariance is manifest, and the Yang-Mills ghosts are automatically included in loop calculations by worldline ghosts. Inspired by string calculations, we extend the usual worldline approach to incorporate more "generalized" 1D manifolds. This new approach should be useful for constructing higher-point and higher-loop amplitudes.

hep-th↗

arXiv2007

Potential for regulatory genetic networks of gene expression near a stable point

A description for regulatory genetic network based on generalized potential energy is constructed. The potential energy is derived from the steady state solution of linearized Fokker-Plank equation, and the result is shown to be equivalent to the system of coupled oscillators. The correspondence between the quantities from the mechanical picture and the steady-state fluctuations is established. Explicit calculation is given for auto-regulatory networks in which, the force constant associated with the degree of protein is very weak. Negative feedback not only suppresses the fluctuations but also increases the steepness of the potential. The results for the fluctuations agree completely with those obtained from linear noise Fokker-Planck equation.

physics.bio-ph↗

arXiv2007

Running anti-de Sitter radius from QCD-like strings

We consider renormalization effects for a bosonic QCD-like string, whose partons have $1/p^{2}$ propagators instead of Gaussian. Classically this model resembles (the bosonic part of) the projective light-cone (zero-radius) limit of a string on an AdS${}_5$ background, where Schwinger parameters give rise to the fifth dimension. Quantum effects generate dynamics for this dimension, producing an AdS${}_5$ background with a running radius. The projective light-cone is the high-energy limit: Holography is enforced dynamically.

hep-th↗

arXiv2006

String interactions on the random lattice

We combine two partons on a random lattice as a vector state. In the ladder approximation, we find that such states have 1/p^2 propagators (after tuning the mass to vanish). We also construct some diagrams which are very similar to 3-string vertices in string field theory for the first oscillator mode. Attaching 3 such lattice states to these vertices, we get Yang-Mills and F^3 interactions up to 3-point as from bosonic string (field) theory. This gives another view of a gauge field as a bound state in a theory whose only fundamental fields are scalars.

hep-th↗

arXiv2006

N=4 SYM NMHV Loop Amplitude in Superspace

Here we construct N=4 SuperYang-Mills 6 point NMHV loop amplitude (amplitudes with three minus helicities) as a full superspace form, using the $SU(4)_{R}$ anti-commuting spinor variables. Amplitudes with different external particle and cyclic helicity ordering are then just a particular expansion of this fermionic variable. We've verified this by explicit expansion obtaining amplitudes with two gluino calculated before. We give results for all gluino $A(Λ^{-}Λ^{-}Λ^{-}Λ^{+}Λ^{+}Λ^{+})$and all scalar $A(ϕϕϕϕϕϕ)$scattering amplitude. A discussion of using MHV vertex approach to obtain these amplitudes are given, which implies a simplification for general loop amplitudes.

hep-th↗