18 research outputs found
ADHM Construction of (Anti-)Self-dual Instantons in Eight Dimensions
We study the ADHM construction of (anti-)self-dual instantons in eight
dimensions. We propose the general scheme to construct the (anti-)self-dual
gauge field configurations whose finite
topological charges are given by the fourth Chern number. We show that our
construction reproduces the known one-instanton solution. We
also construct multi-instanton solutions of 't Hooft and Jackiw-Nohl-Rebbi
(JNR) types in the dilute instanton gas approximation. The well-separated
configurations of multi-instantons reproduce the correct topological charges
with high accuracy. We also show that our construction is generalized to
(anti-)self-dual instantons in dimensions.Comment: 35 pages, 1 figure, minor correction
Atiyah-Manton construction of Skyrmions in eight dimensions
We show that the eight-dimensional instanton solution, which satisfies the
self-duality equation , realizes the static
Skyrmion configuration in eight dimensions through the Atiyah-Manton
construction. The relevant energy functional of the Skyrme field is obtained by
the formalism developed by Sutcliffe. By comparing the Skyrmion olution
associated with the extreme of the energy, with the Atiyah-Manton solution
constructed by the instantons, we find that they agree with high accuracy. This
is a higher-dimensional analogue of the Atiyah-Manton construction of Skyrmions
in four dimensions. Our result indicates that the instanton/Skyrmion
correspondence seems to be an universal property in
dimensions.Comment: 23 pages, 5 figures, published versio
HB UBE-4 (α 116 GLU→ALA): A SECOND INDEPENDENT INSTANCE OF A KOREAN FAMILY DISCOVERED BY HEMOGLOBIN SCREENINGS IN OKAYAMA DISTRICT
Resident's Consciousness Regarding Environmental Functions of Bamboo Forest in New-town of Urban Area
Effect of atmospheric-controlled induction-heating fine particle peening on wear resistance and fatigue properties of maraging steel fabricated by laser powder-bed fusion
Maraging steel components fabricated by laser powder-bed fusion, which is a technique of additive manufacturing, are expected to be used widely because of their high strength, hardness and toughness. To apply maraging steel manufactured by laser powder-bed fusion in wider industrial fields and prevent the components from fracture, a study was conducted to improve the wear resistance and fatigue properties of the steel by an atmospheric-controlled induction-heating fine particle peening surface modification technique. The technique developed can create hard intermetallic compound layers and introduce peening effects, which are expected to improve the wear resistance and fatigue properties of maraging steel fabricated by laser powder-bed fusion. The prepared specimens were examined using optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, laser microscopy, X-ray diffraction, micro-Vickers hardness testing, nano-indentation testing, reciprocating ball-on-disk wear tests and axial fatigue tests. It was revealed that atmospheric-controlled induction-heating fine particle peening using mechanically milled particles formed Fe–Al intermetallic compound layers with high hardness, introduced compressive residual stresses and increased the hardness of the maraging steel substrate owing to age hardening. In conclusion, atmospheric-controlled induction-heating fine particle peening can simultaneously improve the wear resistance and fatigue properties of maraging steel fabricated by laser powder-bed fusion within a few minutes. These achievements can expand applications of maraging steel fabricated by laser powder-bed fusion