Gravitinos from Heavy Scalar Decay

Cosmological issues of the gravitino production by the decay of a heavy scalar field $X$ are examined, assuming that the damped coherent oscillation of the scalar once dominates the energy of the universe. The coupling of the scalar field to a gravitino pair is estimated both in spontaneous and explicit supersymmetry breaking scenarios, with the result that it is proportional to the vacuum expectation value of the scalar field in general. Cosmological constraints depend on whether the gravitino is stable or not, and we study each case separately. For the unstable gravitino with $M_{3/2} \sim$ 100GeV--10TeV, we obtain not only the upper bound, but also the lower bound on the reheating temperature after the $X$ decay, in order to retain the success of the big-bang nucleosynthesis. It is also shown that it severely constrains the decay rate into the gravitino pair. For the stable gravitino, similar but less stringent bounds are obtained to escape the overclosure by the gravitinos produced at the $X$ decay. The requirement that the free-streaming effect of such gravitinos should not suppress the cosmic structures at small scales eliminates some regions in the parameter space, but still leaves a new window of the gravitino warm dark matter. Implications of these results to inflation models are discussed. In particular, it is shown that modular inflation will face serious cosmological difficulty when the gravitino is unstable, whereas it can escape the constraints for the stable gravitino. A similar argument offers a solution to the cosmological moduli problem, in which the moduli is relatively heavy while the gravitino is light.Comment: 14 pages, 8 figure

Experimental practice using 3D scanning for understanding the structure of a stone chamber from the Kofun period, Japan – A case study of the Shobuzako Kofun, Okayama prefecture –

[EN] The Shobuzako Kofun, located in Okayama prefecture (western Japan), is a key-hole tomb set on a low rolling hill dating to the 5th century AD. Its stone chamber and burial goods are in very good condition because the stone chamber has not been looted.In this presentation, we will indicate a case study of the experimental use of 3D measuring techniques for recording and understanding the structure of a stone chamber, as well as the layout of burial goods’ layers in the Shobuzako Kofun. We will show some of the benefits and problems of 3D measuring techniques, and the basic remarks for using this method.[ES] El Shobuzaku Kofun, localizado en la prefectura de Okayama (Japón occidental), es una tumba con forma de “ojo de cerradura” construido sobre un montículo natural y está fechado en el siglo V d.c. Su cámara funeraria de piedra y artefactos asociados están en muy buena condición dado que la cámara no ha sido saqueada.En esta presentación, nosotros presentaremos un caso experimental del uso de técnicas de medida en 3D para registrar y entender la estructura de una cámara funeraria de piedra, así como la distribución de objetos asociados a la tumba en el Shobuzaku Kofun. Presentaremos algunos de los beneficios y problemas de las técnicas de medida en 3D, y las observaciones principales al usar este método.Yamaguchi, Y.; Matsugi, T. (2010). Experimental practice using 3D scanning for understanding the structure of a stone chamber from the Kofun period, Japan – A case study of the Shobuzako Kofun, Okayama prefecture –. Virtual Archaeology Review. 1(2):43-46. https://doi.org/10.4995/var.2010.4684OJS434612Archaeological Institute of Kashihara, Nara Prefecture (2005): Sanjigen Dejitaru Akaibu wo Katsuyou-Shita Kokyou no Sougouteki Kenkyu (A general study of old mirrors by three-dimensional digital archive technology), Bulletin of the Archaeological Institute of Kashihara, Vol.8.BESSHO Hidetaka and MATSUGI Takehiko (2008): "Material source of stone chamber elements and the burial mound of the Shobuzako Kofun, Okayama Prefecture, western Japan (abstract)", in WAC6, Ireland 2008, Sixth World Archaeological Congress (proglam). Dublin.MATSUGI Takehiko (ed.) (2001): Kibi Chiiki ni Okeru "Yuryaku-Cho" Ki no Kokogaku-teki Kenkyu (Archaeological research into the Yuryakudynasty period in Kibi Region): Kagaku Kekyui Hojokin (Kiban Kenkyu(B)(2)) Kenkyu Seika Hokokusho, Heisei 9 Nendo -Heisei 12 Nendo, Okayama.MATSUGI Takehiko (ed.) (2008): Mitokutsu Kofun no Hakkutsu Chosa, Shobuzako Kofun Dai 5 Ji Hakkutsu Chosa (Shobuzako tumulus excavation report 1-5th excavation, 2001-2005 Okayama, Japan.), Faculty of Letters, Okayama University.NIIRO Izumi (ed) (2008): Okayama-shi Zozan Kofun Sokuryo Chosa Gaihou (A preliminary report of Zozan Kofun, Okayama city, Okayama prefecture, Japan), Kagaku Kekyui Hojokin Kiban Kenkyu(B) Kenkyu Seika Hokokusho.OKSBERG, Jane (2007): "The Last Excavation at Shobuzako Kofun.", in Bulletin of the Society for East Asian Archaeology ,Vol.1, the Society for East Asian Archaeology, pp.35-48.SEIKE Akira (ed.) (2006): Nankoku-shi ni Okeru Ogata Koki Kofun no Chosa. (The investigations of large-scaled Late Kofun in Nankoku city, Kochi Prefectue, Japan.), Kochi Daigaku Kokogaku Kenkyushitsu

Endoscopic Nd:YAG Laser Treatment in the Perioperative Management of Tracheobronchoplasty

The objective of this study was to determine the role of endoscopic Nd:YAG laser treatment in the preoperative or postoperative management of tracheobronchoplasty. Eighteen patients with severe stenotic lesions of the trachea or bronchus underwent Nd:YAG laser treatment. Nd:YAG laser treatment was performed in the preoperative period in 14 patients and in the postoperative period in 4 patients. The indications for Nd:YAG laser treatment included emergency airway dilatation, confirmation of the distal margin of tumor, and safe tracheal intubation in patients with severe tracheal stenosis. The indications for Nd:YAG laser treatment in patients with severe stenosis of the mainstem bronchus were confirmation of the distal margin of tumor and recovery of lung ventilation during the preoperative period and reopening of the bronchial lumen to prevent obstructive pneumonia in the postoperative period. Among patients treated with Nd:YAG laser preoperatively, the indications were completely achieved in all 14 patients, except for 1 patient with adenoid cystic carcinoma who underwent treatment of the right mainstem bronchus. Among patients treated with Nd:YAG laser postoperatively the indications also were achieved in all 4 patients with severe granulomatous stenosis of the bronchial end-to-end anastomosis following sleeve lobectomy. In conclusion, endoscopic Nd:YAG laser treatment played an important role in the perioperative management of patients undergoing tracheobronchoplasty

Large-scale SPH simulations of droplet impact onto a liquid surface up to the consequent formation of Worthington jet

In this study, the whole process of liquid droplet impact onto a liquid surface up to the consequent formation of the central column was simulated using the smoothed particle hydrodynamics method (SPH), and compared with an experiment using a high-speed video camera. The surface tension tensor for the particle-based expression was adequately included as the gradient of the surface tension and that enabled the simulation leading to the formations of crater and crown as well as the consequent central column. The simulated time series of the crater depth and diameter and crown height corresponded quantitatively well with the experimental result up to the rebound motion while discrepancies remained as a lower central column height in the simulation, and this seemed to be ascribed to the difficulty in realizing the complex surface structure that inevitably appeared in the fast rebound motion

Population pressure and prehistoric violence in the Yayoi period of Japan

The causes of prehistoric inter-group violence have been a subject of long-standing debate in archaeology, an- thropology, and other disciplines. Although population pressure has been considered as a major factor, due to the lack of available prehistoric data, few studies have directly examined its effect so far. In the present study, we used data on skeletal remains from the middle Yayoi period of the Japanese archipelago, where archaeologists argued that an increase of inter-group violence in this period could be explained by a population-pressure hy- pothesis. We quantitatively examine the effect of population pressure on the frequency of inter-group violence by compiling an exhaustive data set. We collected demographic information based on burial jars (kamekan) and the frequency of violence based on the ratio of injured individuals. The results are consistent with the hypothesis, i. e., high population density can promote inter-group violence