arXiv subjects
Publications and source records attributed to Jae-weon Lee.
The equation describing the stochastic motion of a classical particle in 1+1-dimensional space-time is connected to the Dirac equation with external gauge fields. The effects of assigning different turning probabilities to the forward and the backward moving particles in time are discussed.
Identifying the Bolch sphere with the Riemann sphere(the extended complex plane), we obtain relations between single qubit unitary operations and Möbius transformations on the extended complex plane.
We consider a quantum circuit in which shift and rotation operations on qubits are performed by swap gates and controlled swap gates. These operations can be useful for quantum computers performing elementary arithmetic operations such as multiplication and a bit-wise comparison of qubits.
The first order phase transition proceeds via nucleation and growth of true vacuum bubbles. When charged particles collide with the bubble they could radiate electromagnetic wave. We show that, due to an energy loss of the particles by the radiation, the damping pressure acting on the bubble wall depends on the velocity of the wall even in a thermal equilibrium state.
The oscillating inflation model recently proposed by Damour and Mukhanov is investigated with a non-minimal coupling. Numerical study confirms an inflationary behavior and the density perturbation is obtained. A successful inflation requires the gravity-dilaton coupling to be small.
The open inflation model recently proposed by Hawking and Turok is investigated in scalar-tensor gravity context. If the dilaton-like field has no potential, the instanton of our model is singular but has a finite action. The Gibbons-Hawking surface term vanishes and hence, can not be used to make $Ω_0$ nonzero. To obtain a successful open inflation one should introduce other matter fields or a potential for the dilaton-like fields.
A first order inflation model where a gauge coupling constant runs as the universe inflates is investigated. This model can solve the graceful-exit problem within Einstein gravity by varying the bubble formation rate. The sufficient expansion condition gives group theoretical constraints on the inflaton field, while the appropriate density perturbation requires an additional scalar field or cosmic strings.
An inflation model with inverse symmetry breaking of two scalar fields is proposed. Constraints on the parameters for a successful inflation are obtained. In general the inequality $λ_1\ll g <λ_2$ should be satisfied, where $λ_{1,2}$ and $g$ are the coupling constants for self interaction and mutual interaction of two scalar fields respectively. An example with $SU(5)$ GUTs phase transition and numerical study are presented. This model introduce a new mechanism for the onset of inflation.
We study fermion reflection at a phase wave which is formed during a bubble collision in a first order phase transition. We calculate the reflection and the transmission coefficients by solving the Dirac equation with the phase wave background. Using the results we analyze the damping and the velocity of the wave.
We investigate the boson star with the self-interacting scalar field as a model of galactic halos. The model has slightly increasing rotation curves and allows wider ranges of the mass($m$) and coupling($λ$) of the halo dark matter particle than the non-interacting model previously suggested(ref.\cite{sin1}). Two quantities are related by $λ^{\frac{1}{2}} (m_p/m)^2\st{>}{\sim} 10^{50}$.