arXiv subjects

Hyunbyuk Kim

Publications and source records attributed to Hyunbyuk Kim.

4 recordsLinked to original sources

arXiv2017

Geometrical Interpretation of Electromagnetism in a 5-Dimensional Manifold

In this paper, Kaluza-Klein theory is revisited and its implications are elaborated. We show that electromagnetic 4-potential can be considered as a shearing-like deformation of a 5-dimensional (5D) manifold along the fifth (5th) axis. The charge-to-mass ratio has a physical meaning of the ratio between the movement along the direction of the 5th axis and the movement in the 4D space-time. In order to have a 5D matter which is consistent with the construction of the 5D manifold, a notion of particle-thread is suggested. Examinations on the compatibility of reference frames reveal a covariance breaking of the 5th dimension. The field equations which extend Einstein's field equations give the total energy-momentum tensor as a sum of that of matter, electromagnetic field, and the interaction between electric current and electromagnetic potential. Finally, the experimental implications are calculated for the weak potential case.

gr-qc↗

arXiv2011

How does a drinking straw balance work?

We examine working mechanism of a drinking straw balance. Unlike the usual horizontal level balances which rely on the pivotal rotation, a drinking straw balance shows rolling motion. Because of this rolling and relative position between the pin and the center line of a straw, a new equilibrium state is possible after placement of a test mass. Relative errors between the measured values by a drinking straw balance and an electronic scale are order of 22%. Minimum value of a measurable mass by a straw balance is order of 10 mg.

physics.pop-ph↗

arXiv2010

Falling spring and falling catenary as cases of force propagation

At every points of a static equilibrium system, the net force is zero. If one of the composite forces of this system is disappeared, it is no more in equilibrium and this effect of absence spreads through the system with a finite velocity. So it takes finite time before this absence is manifest at the other points. A frequently asked question may describe this situation well. ``If the Sun disappears abruptly, does this affect us instantly?" In this question centripetal force due to the gravity of the Sun does not disappear simultaneously all over the place, so the Earth sustains its elliptical motion for a while. As this example shows, it is a well known fact that the force does spread with a finite velocity. But for the specific problems it is sometimes not easy to notice this property of the force. To help this, we consider the motion of a falling spring and a falling catenary. We study the conceptual aspects of these motions and apply it to the experimental data. A minimal theoretical background is also treated. For the future, we anticipate that this work would be useful for enhancing the concept of wave motion.

physics.class-ph↗

arXiv2007

Preheating and Affleck-Dine leptogenesis after thermal inflation

Previously, we proposed a model of low energy Affleck-Dine leptogenesis in the context of thermal inflation. The lepton asymmetry is generated at the end of thermal inflation, which occurs at a relatively low energy scale with the Hubble parameter somewhere in the range $1 \keV \lesssim H \lesssim 1 \MeV$. Thus Hubble damping will be ineffective in bringing the Affleck-Dine field into the lepton conserving region near the origin, leaving the possibility that the lepton number could be washed out. Previously, we suggested that preheating could damp the amplitude of the Affleck-Dine field allowing conservation of the lepton number. In this paper, we demonstrate numerically that preheating does efficiently damp the amplitude of the Affleck-Dine field and that the lepton number is conserved as the result. In addition to demonstrating a crucial aspect of our model, it also opens the more general possibility of low energy Affleck-Dine baryogenesis.

hep-ph↗