M. Lorenzini, L. Aiello, E. Cesarini, V. Fafone, D. Lumaca, Y. Minenkov, I. Nardecchia, A. Rocchi, V. Sequino
The performance of present and future gravitational wave detectors is limited by fundamental factors, such as thermal noise, seismic or newtonian noise and quantum nature of light. Besides, technological factors impact the reach of advanced detectors in that upgrade strategies are limited by state-of-art performances. In the realm of optics, the quantum limit to sensitivity will be addressed by injecting higher laser power and by exploiting the capabilities of squeezed light. In turn, technological efforts in the preparation of suitable optics able to meet more and more demandig requirements are ongoing. Moreover, solutions to mitigate the effect of known showstoppers such as parametric instablities are being studied. The present day strategy to correct for residual cold defects in the core optics and to counteract the thermal effects due to power absorption is embedded in a set of sensors and actuators integrated in the Advanced Virgo design, the so called Thermal Compensation System (TCS). This system is designed to be focused on the needs of high power operation of the detector, nonetheless it is highly versatile and can deal with foreseen and unexpected issues. We discuss the features of the TCS with emphasis on its versatility and portability to upgraded detectors; we also present the status of the R&D activity in the Tor Vergata labs, highlighting new applications where the methods of TCS can have a relevant impact, such as adaptive mode matching for squeezing and damping of parametric instabilities.
{"title":"Adaptive optics methods in gravitational wave interferometric detectors, a perspective","authors":"M. Lorenzini, L. Aiello, E. Cesarini, V. Fafone, D. Lumaca, Y. Minenkov, I. Nardecchia, A. Rocchi, V. Sequino","doi":"10.22323/1.325.0008","DOIUrl":"https://doi.org/10.22323/1.325.0008","url":null,"abstract":"The performance of present and future gravitational wave detectors is limited by fundamental \u0000factors, such as thermal noise, seismic or newtonian noise and quantum nature of light. Besides, \u0000technological factors impact the reach of advanced detectors in that upgrade strategies are \u0000limited by state-of-art performances. In the realm of optics, the quantum limit to sensitivity \u0000will be addressed by injecting higher laser power and by exploiting the capabilities of squeezed \u0000light. In turn, technological efforts in the preparation of suitable optics able to meet more and \u0000more demandig requirements are ongoing. Moreover, solutions to mitigate the effect of known \u0000showstoppers such as parametric instablities are being studied. \u0000The present day strategy to correct for residual cold defects in the core optics and to counteract \u0000the thermal effects due to power absorption is embedded in a set of sensors and actuators \u0000integrated in the Advanced Virgo design, the so called Thermal Compensation System (TCS). \u0000This system is designed to be focused on the needs of high power operation of the detector, \u0000nonetheless it is highly versatile and can deal with foreseen and unexpected issues. We discuss \u0000the features of the TCS with emphasis on its versatility and portability to upgraded detectors; we \u0000also present the status of the R&D activity in the Tor Vergata labs, highlighting new applications \u0000where the methods of TCS can have a relevant impact, such as adaptive mode matching for \u0000squeezing and damping of parametric instabilities.","PeriodicalId":147125,"journal":{"name":"Proceedings of Gravitational-waves Science&Technology Symposium — PoS(GRASS2018)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129982334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Cesarini, M. Lorenzini, A. Amato, G. Cagnoli, Q. Cassar, J. Dickmann, M. Granata, V. Fafone, D. Heinert, S. Kroker, D. Lumaca, F. Martelli, L. Mereni, R. Nawrodt, F. Piergiovanni, C. B. R. Hurtado
The visibility distance of interferometric gravitational wave detectors is limited by mirror thermal noise at mid-range frequency, where the first coalescence GW signals have been detected and where many others are expected in the next future. In particular, for enhanced second generation and third generation we need to increase the performance of the test mass multilayer reflective coatings. The Virgo collaboration is setting up a coating R&D group on many issues, including especially metrology (loss angle measurements, thermoelastic effect modeling), new materials (new oxides, nitrates, fluoride, new cosputtered mixing and nanolayered composites) completely characterized (optically, mechanically and morphologically), optimization of deposition parameters, with the aim of developing new coating materials and technologies for the AdVirgo upgrades and for future detectors. Another objective is to understand the losses in amorphous materials, framing coating research in the more general context of the physics of glasses and amorphous materials. One of the developed research lines is the study of thermoelastic damping in crystalline materials, that are promising candidates for cryogenic test masses and particularly suitable substrates for coating research. A detailed discussion on models, based on a semi-analytical calculation starting from the heat diffusion equation, for crystalline substrates will be reported. A new study on the changes in thermoelastic loss after coating deposition, with some preliminary results, will be also reported.
{"title":"The Virgo Coating Collaboration: a detailed study on thermoelasticity in crystalline materials and other research lines","authors":"E. Cesarini, M. Lorenzini, A. Amato, G. Cagnoli, Q. Cassar, J. Dickmann, M. Granata, V. Fafone, D. Heinert, S. Kroker, D. Lumaca, F. Martelli, L. Mereni, R. Nawrodt, F. Piergiovanni, C. B. R. Hurtado","doi":"10.22323/1.325.0006","DOIUrl":"https://doi.org/10.22323/1.325.0006","url":null,"abstract":"The visibility distance of interferometric gravitational wave detectors is limited by mirror thermal \u0000noise at mid-range frequency, where the first coalescence GW signals have been detected and \u0000where many others are expected in the next future. In particular, for enhanced second generation \u0000and third generation we need to increase the performance of the test mass multilayer reflective \u0000coatings. The Virgo collaboration is setting up a coating R&D group on many issues, including \u0000especially metrology (loss angle measurements, thermoelastic effect modeling), new materials \u0000(new oxides, nitrates, fluoride, new cosputtered mixing and nanolayered composites) completely \u0000characterized (optically, mechanically and morphologically), optimization of deposition parameters, \u0000with the aim of developing new coating materials and technologies for the AdVirgo upgrades \u0000and for future detectors. Another objective is to understand the losses in amorphous materials, \u0000framing coating research in the more general context of the physics of glasses and amorphous \u0000materials. One of the developed research lines is the study of thermoelastic damping in crystalline \u0000materials, that are promising candidates for cryogenic test masses and particularly suitable \u0000substrates for coating research. A detailed discussion on models, based on a semi-analytical calculation \u0000starting from the heat diffusion equation, for crystalline substrates will be reported. A \u0000new study on the changes in thermoelastic loss after coating deposition, with some preliminary \u0000results, will be also reported.","PeriodicalId":147125,"journal":{"name":"Proceedings of Gravitational-waves Science&Technology Symposium — PoS(GRASS2018)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133822808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Garufi, M. Bassan, A. Cavalleri, M. D. Laurentis, F. Marchi, R. Rosa, L. Fiore, R. Dolesi, N. Finetti, A. Grado, M. Hueller, L. Marconi, L. Milano, Y. Minenkov, G. Pucacco, R. Stanga, D. Vetrugno, M. Visco, S. Vitale, W. Weber
We describe here the realization and tests of a two stage torsion pendulum facility (nicknamed PETER, from Italian PEndolo Traslazionale E Rotazionale, namely translational and Rotational Pendulum) for the measurement of the Gravitational Reference Sensor (GRS) actuation Cross Talks (CT) for LISA-Pathfinder and its possible evolution. This project started within the ground testing activities for the characterization, before flight, of the GRS of LISA-Pathfinder, where it showed results consistent with what observed on flight. The apparatus could easily evolve to a facility to test small forces/torques on free falling instrumented masses, for future next generation space missions. Here, we will discuss the principle of operation of the double torsion pendulum and the initial goal of the activity, the description of the PETER apparatus, cross -talk measurement technique and results and possible extension to more than 2 DoF
我们在这里描述了用于测量LISA-Pathfinder重力参考传感器(GRS)驱动串扰(CT)的两级扭摆设备(绰号PETER，来自意大利PEndolo Traslazionale E Rotazionale，即平移和旋转摆)的实现和测试及其可能的发展。该项目开始于LISA-Pathfinder的地面测试活动，在飞行前对GRS进行表征，其结果与飞行中观察到的结果一致。该设备可以很容易地发展成一个设备，以测试自由下落的仪器质量上的小力/扭矩，用于未来的下一代太空任务。在这里，我们将讨论双扭摆的工作原理和活动的初始目标，PETER装置的描述，串扰测量技术和结果，以及可能扩展到超过2自由度
{"title":"PETER: a torsion pendulum facility to study small forces/torques on free falling instrumented masses","authors":"F. Garufi, M. Bassan, A. Cavalleri, M. D. Laurentis, F. Marchi, R. Rosa, L. Fiore, R. Dolesi, N. Finetti, A. Grado, M. Hueller, L. Marconi, L. Milano, Y. Minenkov, G. Pucacco, R. Stanga, D. Vetrugno, M. Visco, S. Vitale, W. Weber","doi":"10.22323/1.325.0019","DOIUrl":"https://doi.org/10.22323/1.325.0019","url":null,"abstract":"We describe here the realization and tests of a two stage torsion pendulum facility (nicknamed \u0000PETER, from Italian PEndolo Traslazionale E Rotazionale, namely translational and Rotational \u0000Pendulum) for the measurement of the Gravitational Reference Sensor (GRS) actuation Cross \u0000Talks (CT) for LISA-Pathfinder and its possible evolution. This project started within the ground \u0000testing activities for the characterization, before flight, of the GRS of LISA-Pathfinder, where \u0000it showed results consistent with what observed on flight. The apparatus could easily evolve to \u0000a facility to test small forces/torques on free falling instrumented masses, for future next generation \u0000space missions. Here, we will discuss the principle of operation of the double torsion \u0000pendulum and the initial goal of the activity, the description of the PETER apparatus, cross -talk \u0000measurement technique and results and possible extension to more than 2 DoF","PeriodicalId":147125,"journal":{"name":"Proceedings of Gravitational-waves Science&Technology Symposium — PoS(GRASS2018)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117328591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Dovale-Álvarez, Daniel D. Brown, A. Jones, C. Mow-Lowry, H. Miao, A. Freise
Atom interferometers employing optical cavities to enhance the beam splitter pulses promise significant advances in science and technology, notably for future gravitational wave detectors. Long cavities, on the scale of hundreds of meters, have been proposed in experiments aiming to become demonstrators for gravitational wave detection at frequencies below 1 Hz, where laser interferometers, such as LIGO, have poor sensitivity. Our group at the Birmingham Institute of Gravitational Wave Astronomy has explored the fundamental limitations of two-mirror cavities for atomic beam splitting, and established upper bounds on the temperature of the atomic ensemble as a function of cavity length and three design parameters: the cavity $g$-factor, the bandwidth, and the optical suppression factor of the first and second order spatial modes. A lower bound to the cavity bandwidth which avoids elongation of the interaction time and maximizes power enhancement was found. An upper limit to cavity length is also found for symmetric two-mirror cavities. These key limitations impact the feasibility of long-baseline detectors, which suffer from a naturally larger bandwidth and worse optical suppression of higher order optical modes. Our findings will aid the design of current and future experiments using this technology, such as the MIGA experiment in Bordeaux. In the future we aim to fully model the effect that the imperfect optical wavefronts have on the atomic transitions.
{"title":"Challenges of gravitational wave detection using long-baseline cavity-assisted large momentum transfer atom interferometry","authors":"M. Dovale-Álvarez, Daniel D. Brown, A. Jones, C. Mow-Lowry, H. Miao, A. Freise","doi":"10.22323/1.325.0016","DOIUrl":"https://doi.org/10.22323/1.325.0016","url":null,"abstract":"Atom interferometers employing optical cavities to enhance the beam splitter pulses promise significant advances in science and technology, notably for future gravitational wave detectors. Long cavities, on the scale of hundreds of meters, have been proposed in experiments aiming to become demonstrators for gravitational wave detection at frequencies below 1 Hz, where laser interferometers, such as LIGO, have poor sensitivity. Our group at the Birmingham Institute of Gravitational Wave Astronomy has explored the fundamental limitations of two-mirror cavities for atomic beam splitting, and established upper bounds on the temperature of the atomic ensemble as a function of cavity length and three design parameters: the cavity $g$-factor, the bandwidth, and the optical suppression factor of the first and second order spatial modes. A lower bound to the cavity bandwidth which avoids elongation of the interaction time and maximizes power enhancement was found. An upper limit to cavity length is also found for symmetric two-mirror cavities. These key limitations impact the feasibility of long-baseline detectors, which suffer from a naturally larger bandwidth and worse optical suppression of higher order optical modes. Our findings will aid the design of current and future experiments using this technology, such as the MIGA experiment in Bordeaux. In the future we aim to fully model the effect that the imperfect optical wavefronts have on the atomic transitions.","PeriodicalId":147125,"journal":{"name":"Proceedings of Gravitational-waves Science&Technology Symposium — PoS(GRASS2018)","volume":"16 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131070334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The first detection of GWs from a binary neutron star merger (GW170817) marked the beginning of the multimessenger astronomy era. A few hours after the GW detection, the observation of an associated electromagnetic counterpart compatible with a kilonova/macronova emission remarkably confirmed our basic picture concerning the ejection of matter and the nucleosynthesis occurring in such a kind of events. At the same time, it gave a first demonstration of the power of a multimessenger analysis in exploiting binary compact mergers as laboratory of fundamental physics. In this contribution, we will present the status of kilonova/macronova modeling in terms of the different ejection mechanisms, and of the associated r-process nucleosynthesis. We will show the impact of the variety of ejecta (both in terms of microphysical properties and spatial distributions) on the light curves, with a particular application to the case of GW170817. This modelling provides complementary information to the GW signal and is crucial to set multimessenger constraints, for example for the equation of state of nuclear matter.
{"title":"Matter ejection and kilonova emission from binary neutron star mergers","authors":"A. Perego","doi":"10.22323/1.325.0033","DOIUrl":"https://doi.org/10.22323/1.325.0033","url":null,"abstract":"The first detection of GWs from a binary neutron star merger (GW170817) marked the beginning of the multimessenger astronomy era. A few hours after the GW detection, the observation of an associated electromagnetic counterpart compatible with a kilonova/macronova emission remarkably confirmed our basic picture concerning the ejection of matter and the nucleosynthesis occurring in such a kind of events. At the same time, it gave a first demonstration of the power of a multimessenger analysis in exploiting binary compact mergers as laboratory of fundamental physics. In this contribution, we will present the status of kilonova/macronova modeling in terms \u0000of the different ejection mechanisms, and of the associated r-process nucleosynthesis. We will show the impact of the variety of ejecta (both in terms of microphysical properties and spatial distributions) on the light curves, with a particular application to the case of GW170817. This modelling provides complementary information to the GW signal and is crucial to set multimessenger constraints, for example for the equation of state of nuclear matter.","PeriodicalId":147125,"journal":{"name":"Proceedings of Gravitational-waves Science&Technology Symposium — PoS(GRASS2018)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130335704","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During the second scientific run (O2) of LIGO/VIRGO collaboration (LVC), an epochal breakthrough occurred when the first binary neutron star (BNS) gravitational wave (GW) event was detected (GW170817) and associated to the weak short GRB170817A detected by the Fermi and Integral satellites. DLT40 was the second of the six groups which independently detected the associated optical kilonova, DLT17ck 11 hours after the GW channel. Multimessenger astronomy, the detection of an astrophysical source with more than one `messenger’ (photons, gravitational waves, neutrinos), has truly begun. In this paper, we report the DLT40 GW follow-up searching results in the LVC O2 season. Two transients have been discovered (DLT17u, DLT17ck) by DLT40 in the process of triggering the GW information and only one is identified as related to the GW event. The paper outlines the DLT40 galaxy prioritization strategy and the procedures developed to search for transient counterpart candidates.
{"title":"Searching electromagnetic counterpart of gravitational waves","authors":"Shengqi Yang","doi":"10.22323/1.325.0037","DOIUrl":"https://doi.org/10.22323/1.325.0037","url":null,"abstract":"During the second scientific run (O2) of LIGO/VIRGO collaboration (LVC), an epochal breakthrough occurred when the first binary neutron star (BNS) gravitational wave (GW) event was detected (GW170817) and associated to the weak short GRB170817A detected by the Fermi and Integral satellites. DLT40 was the second of the six groups which independently detected the associated optical kilonova, DLT17ck 11 hours after the GW channel. Multimessenger astronomy, the detection of an astrophysical source with more than one `messenger’ (photons, gravitational waves, neutrinos), has truly begun. In this paper, we report the DLT40 GW follow-up searching results in the LVC O2 season. Two transients have been discovered (DLT17u, DLT17ck) by DLT40 in the process of triggering the GW information and only one is identified as related to the GW event. The paper outlines the DLT40 galaxy prioritization strategy and the procedures developed to search for transient counterpart candidates.","PeriodicalId":147125,"journal":{"name":"Proceedings of Gravitational-waves Science&Technology Symposium — PoS(GRASS2018)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130027918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The recent detection of gravitational waves has proven the existence of massive stellar black hole binaries (BBHs), but the formation channels of BBHs are still an open question. Here, we investigate the demography of BBHs by using our new population-synthesis code MOBSE. MOBSE is an updated version of the widely used binary population-synthesis code BSE (Hurley et al. 2000, Hurley et al. 2002) and includes the key ingredients to determine the fate of massive stars: up-to-date stellar wind prescriptions and supernova models. With MOBSE, we form BBHs with total mass up to $sim{}120$ M$_odot$ at low metallicity, but only systems with total mass up to $sim{}80$ M$_odot$ merge in less than a Hubble time. Our results show that only massive metal-poor stars ($Zlesssim 0.002$) can be the progenitors of gravitational wave events like GW150914. Moreover, we predict that merging BBHs form much more efficiently from metal-poor than from metal-rich stars.
最近对引力波的探测已经证明了大质量恒星黑洞双星(BBHs)的存在，但BBHs的形成渠道仍然是一个悬而未决的问题。在这里，我们使用我们新的人口合成代码MOBSE来调查bbh的人口统计学。MOBSE是广泛使用的双星群合成代码BSE (Hurley et al. 2000, Hurley et al. 2002)的更新版本，包括决定大质量恒星命运的关键成分:最新的恒星风处方和超新星模型。通过MOBSE，我们可以在低金属丰度下形成总质量高达$sim{}120$ M $_odot$的bbh，但只有总质量高达$sim{}80$ M $_odot$的系统才会在不到哈勃时间内合并。我们的研究结果表明，只有大质量的贫金属恒星($Zlesssim 0.002$)才能成为GW150914这样的引力波事件的起源。此外，我们预测，与富金属恒星相比，贫金属恒星形成合并黑洞的效率要高得多。
{"title":"Unravelling the progenitors of merging black hole binaries","authors":"N. Giacobbo, M. Mapelli, M. Spera","doi":"10.22323/1.325.0027","DOIUrl":"https://doi.org/10.22323/1.325.0027","url":null,"abstract":"The recent detection of gravitational waves has proven the existence of massive stellar black hole binaries (BBHs), but the formation channels of BBHs are still an open question. Here, we investigate the demography of BBHs by using our new population-synthesis code MOBSE. MOBSE is an updated version of the widely used binary population-synthesis code BSE (Hurley et al. 2000, Hurley et al. 2002) and includes the key ingredients to determine the fate of massive stars: up-to-date stellar wind prescriptions and supernova models. With MOBSE, we form BBHs with total mass up to $sim{}120$ M$_odot$ at low metallicity, but only systems with total mass up to $sim{}80$ M$_odot$ merge in less than a Hubble time. Our results show that only massive metal-poor stars ($Zlesssim 0.002$) can be the progenitors of gravitational wave events like GW150914. Moreover, we predict that merging BBHs form much more efficiently from metal-poor than from metal-rich stars.","PeriodicalId":147125,"journal":{"name":"Proceedings of Gravitational-waves Science&Technology Symposium — PoS(GRASS2018)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128656210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Glaser, Klara T. Knupfer, L. Maczewsky, Max Mausezahl, R. Nawrodt, G. Cole, J. Dickmann, S. Kroker
We present a method to calculate the power spectral density of Brownian noise in complex optomechanical systems using Levin's approach of virtual pressure and present first mechanical loss measurements for high-purity GaAs over a wide temperature range from 7 K to 250 K. The loss reveals three Debye loss peaks. Each peak corresponds to an Arrhenius-like relaxation process with activation energies of 17.9 meV, 65.4 meV and 123 meV respectively. Additional light induced damping was observed for photon energies below and above the fundamental gap of GaAs in contrast to observations by Okamoto et al.
{"title":"Thermal noise in complex systems","authors":"R. Glaser, Klara T. Knupfer, L. Maczewsky, Max Mausezahl, R. Nawrodt, G. Cole, J. Dickmann, S. Kroker","doi":"10.22323/1.325.0010","DOIUrl":"https://doi.org/10.22323/1.325.0010","url":null,"abstract":"We present a method to calculate the power spectral density of Brownian noise in complex optomechanical systems using Levin's approach of virtual pressure and present first mechanical loss measurements for high-purity GaAs over a wide temperature range from 7 K to 250 K. The loss reveals three Debye loss peaks. Each peak corresponds to an Arrhenius-like relaxation process with activation energies of 17.9 meV, 65.4 meV and 123 meV respectively. Additional light induced damping was observed for photon energies below and above the fundamental gap of GaAs in contrast to observations by Okamoto et al.","PeriodicalId":147125,"journal":{"name":"Proceedings of Gravitational-waves Science&Technology Symposium — PoS(GRASS2018)","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122586241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daniel G. Figueroa, E. Megías, G. Nardini, M. Pieroni, M. Quirós, A. Ricciardone, G. Tasinato
We forecast the prospective of detection for a stochastic gravitational wave background sourced by cosmological first-order phase transitions. We focus on first-order phase transitions with negligible plasma effects, and consider the experimental infrastructures built by the end of the LISA mission. We make manifest the synergy among LISA, pulsar time array experiments, and ground-based interferometers. For phase transitions above the TeV scale or below the electroweak scale, LISA can detect the corresponding gravitational wave signal together with Einstein Telescope, SKA or even aLIGO-aVIRGO-KAGRA. For phase transitions at the electroweak scale, instead, LISA can be the only experiment observing the gravitational wave signal. In case of detection, by using a parameter reconstruction method that we anticipate in this work, we show that LISA on its own has the potential to determine when the phase transition occurs and, consequently, the energy scale above which the standard model of particle physics needs to be modified. The result may likely guide the collider community in the post-LHC era.
{"title":"LISA as a probe for particle physics: electroweak scale tests in synergy with ground-based experiments","authors":"Daniel G. Figueroa, E. Megías, G. Nardini, M. Pieroni, M. Quirós, A. Ricciardone, G. Tasinato","doi":"10.22323/1.325.0036","DOIUrl":"https://doi.org/10.22323/1.325.0036","url":null,"abstract":"We forecast the prospective of detection for a stochastic gravitational wave background sourced by cosmological first-order phase transitions. We focus on first-order phase transitions with negligible plasma effects, and consider the experimental infrastructures built by the end of the LISA mission. We make manifest the synergy among LISA, pulsar time array experiments, and ground-based interferometers. For phase transitions above the TeV scale or below the electroweak scale, LISA can detect the corresponding gravitational wave signal together with Einstein Telescope, SKA or even aLIGO-aVIRGO-KAGRA. For phase transitions at the electroweak scale, instead, LISA can be the only experiment observing the gravitational wave signal. In case of detection, by using a parameter reconstruction method that we anticipate in this work, we show that LISA on its own has the potential to determine when the phase transition occurs and, consequently, the energy scale above which the standard model of particle physics needs to be modified. The result may likely guide the collider community in the post-LHC era.","PeriodicalId":147125,"journal":{"name":"Proceedings of Gravitational-waves Science&Technology Symposium — PoS(GRASS2018)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115282283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Massive black hole binaries (BHBs) are expected to form as the result of galaxy mergers; they shrink via dynamical friction and stellar scatterings, until gravitational waves (GWs) bring them to the final coalescence. It has been argued that BHBs may stall at a parsec scale and never enter the GW stage if stars are not continuously supplied to the BHB loss cone. Here we perform several N-body experiments to study the effect of an 80,000 solar masses stellar cluster (SC) infalling on a parsec-scale BHB. We explore different orbital elements for the SC and we perform runs both with and without accounting for the influence of a rigid stellar cusp (modelled as a rigid Dehnen potential). We find that the semi-major axis of the BHB shrinks by more than 10 per cent if the SC is on a nearly radial orbit; the shrinking is more efficient when a Dehnen potential is included and the orbital plane of the SC coincides with that of the BHB. In contrast, if the SC orbit has non-zero angular momentum, only a few stars enter the BHB loss cone and the resulting BHB shrinking is negligible. Our results indicate that SC disruption might significantly contribute to the shrinking of a parsec-scale BHB only if the SC approaches the BHB on a nearly radial orbit.
{"title":"Star Cluster Disruption by a Supermassive Black Hole Binary","authors":"E. Bortolas, M. Mapelli, M. Spera","doi":"10.22323/1.325.0030","DOIUrl":"https://doi.org/10.22323/1.325.0030","url":null,"abstract":"Massive black hole binaries (BHBs) are expected to form as the result of galaxy mergers; they shrink via dynamical friction and stellar scatterings, until gravitational waves (GWs) bring them to the final coalescence. It has been argued that BHBs may stall at a parsec scale and never enter the GW stage if stars are not continuously supplied to the BHB loss cone. Here we perform several N-body experiments to study the effect of an 80,000 solar masses stellar cluster (SC) infalling on a parsec-scale BHB. We explore different orbital elements for the SC and we perform runs both with and without accounting for the influence of a rigid stellar cusp (modelled as a rigid Dehnen potential). We find that the semi-major axis of the BHB shrinks by more than 10 per cent if the SC is on a nearly radial orbit; the shrinking is more efficient when a Dehnen potential is included and the orbital plane of the SC coincides with that of the BHB. In contrast, if the SC orbit has non-zero angular momentum, only a few stars enter the BHB loss cone and the resulting BHB shrinking is negligible. Our results indicate that SC disruption might significantly contribute to the shrinking of a parsec-scale BHB only if the SC approaches the BHB on a nearly radial orbit.","PeriodicalId":147125,"journal":{"name":"Proceedings of Gravitational-waves Science&Technology Symposium — PoS(GRASS2018)","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124014135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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