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= GW research exchange meeting =
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== 重力波研究交流会とは? ==
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 * [[gw_talks/what_is|重力波研究交流会とは?]]  * [[gw_talks/what_is|What is GW REM? (重力波研究交流会とは?)]]
 * [[#UsefulLinks | Useful Links ]]
 * [[#HowToAnnouncements | How to receive announcements ]]
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<<BR>>
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== Upcoming GW-REMs ==
----
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== 次回の重力波研究交流会 ==
== The past GW REM talks ==
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=== 第78回 2015年8月21日(金) ===

----

 * 場所 東大安東研

 * 時間 13:00-14:00

 * Talk : 井上優貴 (KEK)
  *「宇宙マイクロ波背景放射偏光観測実験POLARBEAR-2の開発と評価」

 * Seevogh 接続情報
  *Title: JGW monthly seminar
  *Community: Virgo - LSC
  *Password: 案内メールを参照のこと
  *Meeting Access Information:
<<Include(gw_talks/archive_111_120)>>
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== 過去の重力波研究交流会 ==
----
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=== 第77回 2015年7月24日(金) ===
== Archives for the past talks ==
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 * 場所 国立天文台

 * 時間 13:00-15:00

 * 登壇者1:Mark Barton (国立天文台)
  * タイトル: "Suspension Dynamics Modeling for LIGO and KAGRA"[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3768|発表ファイル]]
  * 概要: A description of work I did on suspension dynamics modeling at LIGO with particular emphasis on its relation to Sekiguchi-san's adaptation and other things that will be needed for KAGRA.

 * 登壇者2:Manuel Marchio (東大天文D1)
  * タイトル: "Bayesian approach to the locking problem for high-finesse optical cavities"[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3863|発表ファイル]]
  * 概要 : To Be Announced

 * Seevogh 接続情報
  *Title:
  *Community: Virgo - LSC
  *Password: 案内メールを参照のこと
  *Meeting Access Information:



=== 第76回 2015年5月8日(金) ===

----

 * 場所 東大宇宙線研

 * 時間 13:00-15:00

 * Talk1: James Quach(物性研究所)「Gravitational Casimir Effect」[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3531|発表ファイル]]

 * Talk2: 小野謙次(宇宙線研究所)「New estimation method for mass of an isolated neutron star using gravitational waves」[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3535|発表ファイル]]



 * Seevogh 接続情報
  *Title:JGW monthly seminar
  *Community: Virgo - LSC
  *Password: 案内メールを参照のこと
  *Meeting Access Information:


=== 第75回 2015年4月24日(通常より1時間遅いスタートとなります。) ===

----

 * 場所 東工大宗宮研

 * 時間 14:00-16:00

 * Talk1: 矢野和城 (宗宮研M2)
  *「宗宮研でやっている実験レビュー (信号増幅を中心に)」[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3511|発表ファイル]]

 * Talk2: 橘優太朗 (河合研M2)
  *「光子で探る活動銀河核(時系列解析を中心に)」[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ProcessDocumentAdd|発表ファイル]]

 * Seevogh 接続情報
  *Title: JGW monthly seminar
  *Community: Virgo - LSC
  *Password: 案内メールを参照のこと
  *Meeting Access Information:
    *SeeVoghRN Application http://research.seevogh.com/joinSRN?meeting=M9MIMi222iDeDi999iDD99
    *Mobile App : Meeting ID: 727 4165 or Link: http://research.seevogh.com/join?meeting=M9MIMi222iDeDi999iDD99



=== 第74回 2015年2月20日(金) ===
----

 * 場所 東大三尾研

 * 時間 13:00-15:00

 * Talk1: 水谷彬(三尾研M1)
  *「フェムト秒レーザーによるCFRPのレーザー加工」[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3332|発表ファイル]]
 * Seevogh 接続情報
  *Title: JGW monthly seminar
  *Community: Virgo - LSC
  *Password: 案内メールを参照のこと
  *Meeting Access Information:
    *SeeVoghRN Application http://research.seevogh.com/joinSRN?meeting=M9MIMi222iD2D29I99DD99
    *WebStart (Java) http://research.seevogh.com/join?meeting=M9MIMi222iD2D29I99DD99
    *Mobile App : Meeting ID: 721 8680 or Link: http://research.seevogh.com/join?meeting=M9MIMi222iD2D29I99DD99




=== 第73回 2015年1月23日(金)〜冬のIMC祭り〜 ===
----

 * 場所 Seevogh上

 * 時間 13:00-15:00

 * Talk1:苔山圭以子(Louisiana State Univ.)
  *「aLIGO (LLO) IMC Overview」[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB//ShowDocument?docid=3258|発表ファイル]]

 * Talk2:中野雅之(宇宙線研)
  *「Installation of KAGRA PSL table」[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3256|発表ファイル]]

 * Talk3:斉藤高大(新潟大)
  *「KAGRA IMC suspension report」[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3257|発表ファイル]]

 * Seevogh 接続情報
  *Title: JGW monthly seminar
  *Community: Virgo - LSC
  *Password: 案内メールを参照のこと
  *Meeting Access Information:
    *SeeVoghRN Application http://research.seevogh.com/joinSRN?meeting=MsMiMI2l2eDMDv9n9aDt9s
    *WebStart (Java) http://research.seevogh.com/join?meeting=MsMiMI2l2eDMDv9n9aDt9s
    *Mobile App : Meeting ID: 719 6573 or Link: http://research.seevogh.com/join?meeting=MsMiMI2l2eDMDv9n9aDt9s



=== 第72回 2014年12月19日(金) ===
----

 * 場所 東大宇宙線研

 * 時間 13:00-15:00

 * Talk1:土井康平(宇宙線研究所) 発表資料:なし

 * Talk2:和泉究(LIGO ハンフォード)[[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3117|発表資料]]

 * Seevogh (evo) 接続情報
  *Title: JGW Monthly Seminar
  *Community: Virgo-LSC
  *Password: アナウンスメールを参照して下さい。
  *Meeting Access Information:



=== 第71回 2014年11月21日 ===
----

 * 場所 東京大学安東研

 * 時間 13:00-15:00

 * Talk1: 宇佐見康二(東大先端研)
  *「光-マグノン-マイクロ波-超伝導量子ビットのリンクあるいは量子ピタゴラスイッチ」 [[http://gwdoc.icrr.u-tokyo.ac.jp/DocDB/0030/G1403012/001/2014_11_21_Hongo_n.pdf| 発表資料]]

 * Talk2: 和泉究(LIGO Hanford)
  *「LIGO Hanford での signal recycling cavity 内 mode hop 問題について(仮)」 [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=2995| 発表資料]]

 * Seevogh (evo) 接続情報
  *Title: JGW Monthly Seminar(true)
  *Community: Virgo - LSC
  *Password: アナウンスメールを参照してください。
  *Meeting Access Information:
   *SeeVoghRN Application http://research.seevogh.com/joinSRN?meeting=MMMeMn2D2iDMDu929lD29M
   *WebStart (Java) http://research.seevogh.com/join?meeting=MMMeMn2D2iDMDu929lD29M
   *Mobile App : Meeting ID: 713 3002 or Link: http://research.seevogh.com/join?meeting=MMMeMn2D2iDMDu929lD29M
 * Most of the archives for the earlier years are written in Japanese (it is a history!).
  . {i} [[gw_talks/archive_121_130|121-130th GW-REM talks (2024-)]]
  . {i} [[gw_talks/archive_111_120|111-120th GW-REM talks (2023-2024)]]
  . {i} [[gw_talks/archive_101_110|101-110th GW-REM talks (2019-2022)]]
  . {i} [[gw_talks/archive_91_100|91-100th GW-REM talks (2017-2019)]]
  . {i} [[gw_talks/archive_81_90|81-90th GW-REM talks (2016-2017) ]]
  . {i} [[gw_talks/archive_71_80|71-80th GW-REM talks (2014-2015) ]]
  . {i} [[gw_talks/archive_61_70|61-70th GW-REM talks (2013-2014) ]]
  . {i} [[gw_talks/archive_51_60|51-60th GW-REM talks (2012-2013) ]]
  . {i} [[gw_talks/archive_41_50|41-50th GW-REM talks (2011-2012) ]]
  . {i} [[gw_talks/archive_31_40|31-40th GW-REM talks (2010-2011) ]]
  . {i} [[gw_talks/archive_21_30|21-30th GW-REM talks (2009-2010) ]]
  . {i} [[gw_talks/archive_11_20|11-20th GW-REM talks (2008-2009) ]]
  . {i} [[gw_talks/archive_1_10|1-10th GW-REM talks (2007-2008) ]]
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== これ以前の重力波研究交流会 ==
<<Anchor(UsefulLinks)>>
== Useful links ==
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 * [[JGWDoc/HowTo/UpLoadE| How to upload presentation materials to JGW doc database]]
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    {i} [[gw_talks/archive_61_70|第61回~第70回重力波研究交流会]]  * [[ZoomHowTo | How to use Zoom]]
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    {i} [[gw_talks/archive_51_60|第51回~第60回重力波研究交流会]]  * [[LCGT/Meeting/EVOJ| Use of EVO remote connection system (written in Japanese) ]]
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    {i} [[gw_talks/archive_41_50|第41回~第50回重力波研究交流会]]

    {i} [[gw_talks/archive_31_40|第31回~第40回重力波研究交流会]]

    {i} [[gw_talks/archive_21_30|第21回~第30回重力波研究交流会]]

    {i} [[gw_talks/archive_11_20|第11回~第20回重力波研究交流会]]

    {i} [[gw_talks/archive_1_10|第1回~第10回重力波研究交流会]]
 * [[howtouseezuce| How to join KEK community in eZuce]]
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== 暮らしに役立つリンク == <<Anchor(HowToAnnouncements)>>
== How to receive the announcements ==
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 * [[JGWDoc/HowTo/UpLoad | 資料の upload の仕方]]

 * [[LCGT/Meeting/EVOJ| EVO遠隔会議システムの使い方あれこれ]]
 . /!\ One has to subscribe to the mailing list called ''gw_comm'' in order to receive our announcement emails. Please ask one of our organizers for subscription.
 . The organizers can be found in [[gw_talks/what_is|this page]].

SRMface_small.jpg

重力波研究交流会

GW research exchange meeting



Upcoming GW-REMs



The past GW REM talks


back to top page

The 111-120th REM talks


The 120th REM: Jan 11th, 2024, Thursday


  • Time: 11:00-12:00
  • Speaker: M. Tamaki (ICRR)
    • Title: "Suspension Control in KAGRA"

      • Abstract:
        Abstract: Ground-based GW detector uses multi-stage pendulum to suspend the mirror for high vibration isolation ratio. However, control noise of suspension limits the low-frequency sensitivity in KAGRA, though low-frequency region has many strong scientific case. This talk will summarize the suspension control in KAGRA and strategies for suspension control noise reduction.
  • Speaker: M.Yamamoto (Toyama University)
    • Title: "Study of Parametric Instability in KAGRA"

      • Abstract:
        Abstract: To obtain high shot noise sensitivity, the gravitational wave detectors need to store high laser power in the arm cavity. However, This high laser power causes a phenomenon called Parametric Instability(PI).
        
        PI transfers energy from the fundamental optical mode in the arm cavity to the mechanical modes of the mirror. PI has the potential to be an obstacle to higher sensitivity in the future for KAGRA. I will talk about outline of PI and the current status of PI study in KAGRA.

The 119th REM: Dec 7th, 2023, Thursday (KAGRA FWG(Future Working Group) + GWREM joint session)


  • Time: 9:30-10:10
  • Speaker: Marco Meyer-Conde (Osaka Metropolitan University)
    • Title: "Modern machine learning technics and tools in collaboration with CERN"

      • Abstract:
        Abstract: Timely detection of stellar binary mergers is of the highest interest in 
        both astrophysics and nuclear physics. The use of machine learning 
        technics and mature software with the support of an international 
        laboratory (CERN) and its computer science division will enhance the 
        possibilities and push the boundaries of astrophysics researches.

The 118th REM: Oct 19th, 2023, Thursday


  • Time: 11:00-12:00
  • Speaker: Seiji Kawamura (Nagoya University)
    • Title: "Optical-spring quantum locking for DECIGO, juggled interferometer, jiggled interferometer, and displacement-noise-free neutron interferometer"

      • Abstract:
        Abstract: At Nagoya University, we are developing various advanced technologies for future gravitational wave detectors, including optical-spring quantum locking for the space gravitational wave antenna DECIGO, a juggled interferometer, a jiggled interferometer, and a displacement-noise-free neutron interferometer. All of these interferometers aim to enhance low-frequency sensitivity beyond the capabilities of standard detection methods. In this presentation, I will elucidate the fundamental principles of these detection methods and provide an overview of their current status.

The 117th REM: Aug 17th, 2023, Thursday


  • Time: 17:00-18:00
  • Speaker: Keiko Kokeyama (Cardiff University)
    • Title: "History and current shape of the Cardiff group"

      • Abstract:
        Abstract: Cardiff University Gravitational Wave Exploration Institute has been playing a leading role in gravitational wave physics. History and current shape of the group will be reviewed.
  • Speaker: Abhinav Patra (Cardiff University)
    • Title: "Introduction to the QUEST and commissioning updates"

      • Abstract:
        Abstract: The QUantum Enhanced Space-Time (QUEST) experiment is currently being commissioned at Cardiff University. QUEST consists of a pair of co-located tabletop power-recycled Michelson interferometers, each targeting a displacement sensitivity of $2 x 10^{-19}$ m/rtHz at 100 MHz. To achieve this sensitivity, the interferometers utilize high circulating power (10 kW) and squeezing. The main science goal of QUEST is to be sensitive to sub-shot noise stochastic signals. These stochastic signals can be a result of spacetime fluctuations due to quantum gravity, interactions of dark matter with the interferometer optics or ultra-high frequency stochastic gravitational waves.
  • Speaker: Terri Pearce (Cardiff University)
    • Title: "The Polarisation Phase Camera"

      • Abstract:
        Abstract: The Polarisation Phase Camera, PPC, is designed to be a non-invasive way of characterising the birefringence of a material. A table top experiment in Cardiff is conducting a proof of principle study of the PPC, with the aim of installing it at the detector sites. I will discuss the motivations, science and status of the experiment.

The 116th REM: July 27th, 2023, Thursday


  • Time: 11:00-12:00
  • Speaker: Elenna Capote (Syracuse University)
    • Title: "Advanced LIGO Detector Commissioning for O4"

      • Abstract:
        Abstract: Both the LIGO Livingston and LIGO Hanford Observatories have made significant progress in upgrading detector sensitivity in preparation for the fourth observing run. This talk will summarize the various equipment upgrades and detector commissioning efforts performed to achieve the new sensitivity.

The 115th REM: June 22nd, 2023, Thursday


  • Time: 11:00-12:00
  • Speaker: Hiroko Tomoda (Tokyo Univ.)
    • Title: "Optical quantum state generation using waveguide optical parametric amplifiers"

      • Abstract:
        Abstract: Optical quantum information processing (QIP) using continuous variables (CVs) of quadrature amplitudes, is a promising approach for large-scale QIP because of its high efficiency of operation and measurement. However, there are many issues left about a quantum light source for CV QIP such as its programmability and broadbandness. Hence we now develop a new light source that can programmably output various optical quantum states required for CV QIP, using broadband squeezers of waveguide optical parametric amplifiers (OPAs). Conventionally waveguide OPAs cannot be used for optical quantum state generation due to their large loss. However, low-loss broadband OPAs have been recently developed [APL Photon. 5, 036104 (2020)] and have become essential devices in our experiments. In this talk, I will introduce our experimental setup and results of time-varying output squeezing level using the OPA [Opt. Express 31, 2161 (2023)]. In addition, I will show our research progress in generating single-photon states and Schrӧdinger’s cat states.

The 114th REM: June 1st, 2023, Thursday


  • Time: 11:00-12:00
  • Speaker: Hiroki Takeda (Kyoto Univ.)
    • Title: "Probing scalar polarizations in gravitational waves"

      • Abstract:
        Scalar polarization modes of gravitational waves, which are often predicted in the context of the viable extension of gravity, have been actively searched. However, couplings of the scalar modes to the matter are strongly constrained by the fifth-force experiments. Thus, the amplitude of scalar modes in the observed gravitational-wave signal is expected to be significantly suppressed compared to that of the tensor modes. In this talk, we will discuss the implications of the experiments in the solar system on the detectability of scalar modes in gravitational waves from compact binary coalescences. We first claim that the energy carried by the scalar modes at the generation is, at most, that of the tensor modes from the observed phase evolution of the inspiral gravitational waves. Next, we formulate general gravitational-wave propagation with full polarizations and point out that the energy flux hardly changes through propagation as long as the background changes slowly compared to the wavelength of the propagating waves. Finally, we show that the possible magnitude of scalar polarization modes, which can be probed by the ground-based gravitational-wave telescopes, is already severely constrained by the existing gravity tests in the solar system.

The 113rd REM: April 27th, 2023, Thursday


  • Time: 11:00-12:00
  • Speaker: Chihiro Hirose (Niigata Unv.)
    • Title: "Alignment Sensing and Control in KAGRA"

      • Abstract:
        In international joint observation of gravitational waves, it is necessary to increase the simultaneous operation rate of gravitational wave telescopes to measure the direction of arrival of gravitational waves. In Japan's KAGRA, the mirror is suspended by a pendulum for vibration isolation, but the tilt of the mirror causes drift. To stabilize the optical axis, Alignment Sensing and Control (ASC) needs to be introduced. Wavefront sensing is effective in detecting the difference between the resonator axis and the incident optical axis. Also, KAGRA's mirrors are cooled down to 20 K to reduce thermal noise. Therefore, the mirrors are made of sapphire, which has low mechanical loss even at low temperatures. I investigated the effect of birefringence on ASC by measuring Y-arm error signal. I also actually introduced ASC to the arm. In this gravitational exchange meeting I will talk about the effect of birefringence on ASC, and also about ASC for Observation 4 now.

The 112nd REM: Febrary 28th, 2023, Tuseday


  • Time: 17:00-18:00
  • Speaker: Kohei Yamamoto (AEI)
    • Title: "LISA metrology system: Clocks, ranging, and communication"

      • Abstract:
        The Laser Interferometer Space Antenna (LISA) aims to observe gravitational waves in the mHz regime over its 10-year mission time. LISA will operate laser interferometers between three spacecraft. Each spacecraft will utilize independent clocks, which determine the sampling times of onboard devices called phasemeter to extract the interferometric phases and, ultimately, gravitational wave signals. To suppress limiting laser frequency noise due to time-varying unequal arm lengths, phase signals sampled by each phasemeter must be combined in postprocessing to synthesize virtual equal-arm interferometers with the technique called time-delay interferometry (TDI). The synthesis, in turn, requires a synchronization of the independent clocks in postprocessing. For such on-ground data analysis, additional onboard measurements will be introduced on top of primary phase extractions: intersatellite clock-tone transfer and absolute ranging. The ranging technique also enables intersatellite data communication to ease communication between a ground station and LISA. This talk introduces recent experimental studies of these technologies using a hexagonal optical testbed at AEI Hannover.

The 111th REM: January 26th, 2023, Thursday


  • Time: 11:00-12:00
  • Speaker: Hiroki Fujimoto (UTokyo)
    • Title: "Axion dark matter search with laser interferometry"

      • Abstract:
        Researches on cosmology and astrophysics have revealed that more than 80% of the matter in the universe consists of an unknown substance, or dark matter. The nature of dark matter is still unknown and many searches have been conducted for various dark matter candidates. Axion-like particles (ALPs) are undiscovered particles that are well-motivated candidates for ultralight dark matter. The interaction between ALPs and photons slightly causes the rotational oscillation of linearly polarized light, and therefore ALP dark matter can be detected by the measurement of the polarization rotation of a laser beam.
        Recently, some ALP dark matter search experiments using the laser interferometer have been proposed. The basic idea is to use an optical cavity, which can enhance the effective light path and also the duration of the interaction with the ALP dark matter. With this technique, the polarization rotation can be amplified and high-sensitive ALP dark matter search can be conducted.
        In this talk, I will introduce our interferometric ALP dark matter search experiment: DANCE and the search using the gravitational wave detectors.


Archives for the past talks





How to receive the announcements


  • /!\ One has to subscribe to the mailing list called gw_comm in order to receive our announcement emails. Please ask one of our organizers for subscription.

  • The organizers can be found in this page.

gw_talks (last edited 2024-12-10 16:39:02 by ryosuke.sugimoto)