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J. -M. Chung

Publications and source records attributed to J. -M. Chung.

14 recordsLinked to original sources
arXiv2009

Simultaneous inference of Jefimenko's and Maxwell's equations from retardation

Assuming the idea of retardation as an underlying axiom, we investigate how Jefimenko's and Maxwell's equations can be inferred. In the inference, we begin with the retarded versions of Coulomb's and Biot-Savart's field expression as an incomplete, starting ansatz. By calculating and comparing their divergences, curls, and time derivatives, we improve the ansatz. Thus improved ansatz is further improved through the same procedure and the final ansatz fields are identified with Jefimenko's fields. Our inference of Maxwell's equations is in much the same spirit as the derivation of static differential equations (divergences and curls) from the Coulomb's and Biot-Savart's fields known experimentally without knowing their governing laws of the divergence and curl equations.

physics.class-ph↗
arXiv2002

Evaluation of a Class of Two-Scale Three-Loop Vacuum Diagrams

As a generalization of a previous work [Phys. Rev. D. {\bf 59}, 105014 (1999)], we compute analytically a class of three-loop vacuum diagrams with two {\em arbitrarily} different mass scales. We use a decomposition algorithm in which the integrand of the final integral for the third momentum vector, say, $k$, becomes independent of the angles of $k$-vector in spherical polar coordinates. This algorithm proves to be very efficient in obtaining exclusively all $\e$-pole terms of the given diagram.

hep-ph↗
arXiv2002

RG-Improved Three-Loop Effective Potential of the Massive $ϕ^4$ theory

The renormalization group method is applied to the three-loop effective potential of the massive $ϕ^4$ theory in the $\bar{\rm MS}$ scheme in order to obtain the next-next-next-to-leading logarithm resummation. For this, we exploit four-loop parts of the renormalization group functions $β_λ$, $γ_m$, $γ_ϕ$, and $β_Λ$, which were already given to five-loop order via the renormalization of the zero-, two-, and four-point one-particle-irreducible Green's functions, to solve evolution equations for the parameters $λ$, $m^2$, $ϕ$, and $Λ$ within the accuracy of the three-loop order.

hep-th↗
arXiv2001

Reduction of a Class of Three-Loop Vacuum Diagrams to Tetrahedron Topologies

We obtain finite parts (as well as $ε$-pole parts) of massive three-loop vacuum diagrams with three-point and/or four-point interaction vertices by reducing them to tetrahedron diagrams with both massive and massless lines, whose finite parts were given analytically in a recent paper by Broadhurst. In the procedure of reduction, the method of integration-by-parts recurrence relations is employed. We use our result to compute the $\bar{\rm MS}$ effective potential of the massive $ϕ^4$ theory.

hep-th↗
arXiv2001

Induced Lorentz- and CPT-violating Chern-Simons term in QED: Fock-Schwinger proper time method

Using the Fock-Schwinger proper time method, we calculate the induced Chern-Simons term arising from the Lorentz- and CPT-violating sector of quantum electrodynamics with a $b_μ\barψγ^μγ_5 ψ$ term. Our result to all orders in $b$ coincides with a recent linear-in-$b$ calculation by Chaichian et al. [hep-th/0010129 v2]. The coincidence was pointed out by Chung [Phys. Lett. {\bf B461} (1999) 138] and Pérez-Victoria [Phys. Rev. Lett. {\bf 83} (1999) 2518] in the standard Feynman diagram calculation with the nonperturbative-in-$b$ propagator.

hep-th↗
arXiv1999

Lorentz and CPT Violating Chern-Simons Term in the Derivative Expansion of QED

We calculate by the method of dimensional regularization and derivative expansion the one-loop effective action for a Dirac fermion with a Lorentz-violating and CPT-odd kinetic term in the background of a gauge field. We show that this term induces a Chern-Simons modification to Maxwell theory. Some related issues are also discussed.

hep-th↗
arXiv1999

Radiatively-Induced Lorentz and CPT Violating Chern-Simons Term in QED

We calculate the induced Lorentz- and CPT-violating Chern-Simons term arising from the Lorentz- and CPT-violating sector of quantum electrodynamics with a $b_μ\barψγ^μγ_5ψ$ term. The result to all orders in $b$ coincides with the previous linear-in-$b$ calulation by Chung and Oh [hep-th/9812132] as well as Jackiw and Kostelecký [Phys. Rev. Lett. {\bf 82}, 3572 (1999)], since all higher order terms vanish.

hep-th↗
arXiv1999

Calculation of a Class of Three-Loop Vacuum Diagrams with Two Different Mass Values

We calculate analytically a class of three-loop vacuum diagrams with two different mass values, one of which is one-third as large as the other, using the method of Chetyrkin, Misiak, and Münz in the dimensional regularization scheme. All pole terms in ε=4-D (D being the space-time dimensions in a dimensional regularization scheme) plus finite terms containing the logarithm of mass are kept in our calculation of each diagram. It is shown that three-loop effective potential calculated using three-loop integrals obtained in this paper agrees, in the large-N limit, with the overlap part of leading-order (in the large-N limit) calculation of Coleman, Jackiw, and Politzer [Phys. Rev. D {\bf 10}, 2491 (1974)].

hep-ph↗
arXiv1998

Three-Loop Effective Potential of O(N) $ϕ^4$ Theory

The three-loop effective potential of the massless O(N) $ϕ^4$ theory is calculated analytically using techniques of dimensional regularization. We see a complete agreement between our result and Jackiw's result obtained only up to two-loop order using a different regularization (cutoff regularization) method, but the same renormalization conditions. For an easy check of the mutual cancellation of all the dangerous pole terms in each loop order, we give the $ε$-expanded loop integrals in full detail.

hep-ph↗
arXiv1994

Spontaneous Breaking of Parity in 2+1-Dimensional Thirring Model

A new aspect of the vacuum structure of 2+1-dimensional Thirring model is presented. Using the Fierz identity, we split the current-current four-Fermi interaction in terms of a matrix valued auxiliary scalar field and compute its effective potential. Energy consideration shows that contrary to earlier expectations, parity in general is spontaneously broken at any finite order of N, where N is the number of the two component spinors. In the large N limit, there does not exist a stable vacuum of the theory thereby making the application of the large N limit to Thirring model dangerous. A detailed analysis for parity breaking solutions in N=2,3 cases is given.

hep-th↗