お知らせ

余震にそなえて、しばらくの間、セミナーのほとんどは4号館1階のピロティで行われます。

今後2週間の予定

→カレンダーはこちら
※下記のセミナーの他に新着論文紹介のセミナー(10:00-10:30)が、月曜日、水曜日、金曜日にあります。場所は4号館ピロティです。

2021-04-15 (木) 宇宙物理学セミナー
    UTAPwiki/セミナー/宇宙物理学セミナー Speaker:Daisuke Toyouchi Title:
    Dynamics of an emission centroid during Sgr A* flares Abstract:
    Sgr A* is a supermassive BH in our Galaxy confirmed by long-term monitoring of stellar orbits.
    The luminosity of Sgr A* is usually very small (~10^8 times smaller than its Eddington luminosity), but sometimes it rises up suddenly, so-called flare events. Flares are most noticeable in near-infrared and X-ray bands, where the luminosity increases from a quiescent level of ~10^{33-34} erg/s to a peak level of ~10^{35} erg/s. Although several flare models have been proposed, their origin is still uncertain. Recently, the Gravity collaboration carried out an interferometric observations of NIR flares and detected a motion of an emission centroid with an astrometric accuracy of ~10^{-5} arcsecond. They fit the observed trajectory with a circular Kepler orbit and find the best-fit radius of 7-10 gravitational radius. However, their best-fit orbit lies entirely inside of the trajectory because the small radius is required to reproduce the duration.To resolve this problem, we fit the observed trajectory with different models and I will discuss our results.

2021-04-19 (月) 観測的宇宙論速報
    UTAPwiki/セミナー/観測的宇宙論速報
    担当者:Yoshida
    時間 :10:30-12:00
    場所 :理学部4号館ピロティ前セミナー室
    内容:添付ファイル [添付] 参照 Author(s)TitleYear, Journal,Number(,Link)Y. SutoJinsei Ippan ni Sotairon2010, ISBN978-4-13-063354-3

2021-04-19 (月) 初期宇宙・相対論速報
    UTAPwiki/セミナー/初期宇宙・相対論速報 ============================== Title: Dark Matter and Inflation in Einstein-Cartan Gravity † ↑Speaker: Inar Timiryasov † Abstract: It is known that the gravitational force can be obtained by gauging the Poincaré group. Once the resulting theory – Einstein-Cartan gravity – is coupled to matter, its action contains more terms of mass dimension at most 4 than metric gravity. In this talk, I will discuss them and explore two phenomenological consequences. First, Einstein-Cartan theory generalizes inflationary scenarios driven by the Higgs field. As in the known metric and Palatini models, the resulting predictions agree with observations. Secondly, we obtain a new mechanism for producing singlet fermions in the Early Universe. In a large range of masses, these fermions can constitute all of the dark matter. The seminar will be preceded by three short (one hour) lectures introducing Einstein-Cartan theory and other required tools. References:
    https://arxiv.org/abs/2007.14978
    https://arxiv.org/abs/2007.16158
    https://arxiv.org/abs/2008.11686

2021-04-26 (月) 観測的宇宙論速報
    UTAPwiki/セミナー/観測的宇宙論速報
    担当者:Kashiyama
    時間 :10:30-12:00
    場所 :理学部4号館ピロティ前セミナー室
    内容:添付ファイル [添付] 参照 Author(s)TitleYear, Journal,Number(,Link)Y. SutoJinsei Ippan ni Sotairon2010, ISBN978-4-13-063354-3


セミナー週間予定

10111213141516
新着論文@ピロティ観測的宇宙論速報初期宇宙・相対論速報
新着論文@ピロティ
ランチセミナー昼食会宇宙物理学セミナー
新着論文@ピロティ天体核・素粒子物理速報?


UTAPゼミ週間予定

10111213141516
4年生理論演習
須藤研M1ゼミ(表)
吉田研M1ゼミ



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