A numerical study of stellar discs in galactic nuclei

ArXiv 2207.06398 (2022)

Authors:

Taras Panamarev, Bence Kocsis

Merger rates of intermediate-mass black hole binaries in nuclear star clusters

Astrophysical Journal American Astronomical Society 933:2 (2022) 170

Authors:

Giacomo Fragione, Abraham Loeb, Bence Kocsis, Frederic A Rasio

Abstract:

Repeated mergers of stellar-mass black holes in dense star clusters can produce intermediate-mass black holes (IMBHs). In particular, nuclear star clusters at the centers of galaxies have deep enough potential wells to retain most of the black hole (BH) merger products, in spite of the significant recoil kicks due to anisotropic emission of gravitational radiation. These events can be detected in gravitational waves, which represent an unprecedented opportunity to reveal IMBHs. In this paper, we analyze the statistical results of a wide range of numerical simulations, which encompass different cluster metallicities, initial BH seed masses, and initial BH spins, and we compute the merger rate of IMBH binaries. We find that merger rates are in the range 0.01–10 Gpc−3 yr−1 depending on IMBH masses. We also compute the number of multiband detections in ground-based and space-based observatories. Our model predicts that a few merger events per year should be detectable with LISA, DECIGO, Einstein Telescope (ET), and LIGO for IMBHs with masses ≲1000 M, and a few tens of merger events per year with DECIGO, ET, and LIGO only.

Three-dimensional inhomogeneity of electron-temperature-gradient turbulence in the edge of tokamak plasmas

Nuclear Fusion IOP Publishing 62:8 (2022) 086045

Authors:

Jf Parisi, Fi Parra, Cm Roach, Mr Hardman, AA Schekochihin, Ig Abel, N Aiba, J Ball, M Barnes, B Chapman-Oplopoiou, D Dickinson, W Dorland, C Giroud, Dr Hatch, Jc Hillesheim, J Ruiz Ruiz, S Saarelma, D St-Onge

Abstract:

Nonlinear multiscale gyrokinetic simulations of a Joint European Torus edge pedestal are used to show that electron-temperature-gradient (ETG) turbulence has a rich three-dimensional structure, varying strongly according to the local magnetic-field configuration. In the plane normal to the magnetic field, the steep pedestal electron temperature gradient gives rise to anisotropic turbulence with a radial (normal) wavelength much shorter than in the binormal direction. In the parallel direction, the location and parallel extent of the turbulence are determined by the variation in the magnetic drifts and finite-Larmor-radius (FLR) effects. The magnetic drift and FLR topographies have a perpendicular-wavelength dependence, which permits turbulence intensity maxima near the flux-surface top and bottom at longer binormal scales, but constrains turbulence to the outboard midplane at shorter electron-gyroradius binormal scales. Our simulations show that long-wavelength ETG turbulence does not transport heat efficiently, and significantly decreases overall ETG transport—in our case by ∼40%—through multiscale interactions.

Three-dimensional inhomogeneity of electron-temperature-gradient turbulence in the edge of tokamak plasmas

Nuclear Fusion IOP Publishing 62:8 (2022) 086045-086045

Authors:

Jf Parisi, Fi Parra, Cm Roach, Mr Hardman, Aa Schekochihin, Ig Abel, N Aiba, J Ball, M Barnes, B Chapman-Oplopoiou, D Dickinson, W Dorland, C Giroud, Dr Hatch, Jc Hillesheim, J Ruiz Ruiz, S Saarelma, D St-Onge, JET Contributors

Abstract:

<jats:title>Abstract</jats:title> <jats:p>Nonlinear multiscale gyrokinetic simulations of a Joint European Torus edge pedestal are used to show that electron-temperature-gradient (ETG) turbulence has a rich three-dimensional structure, varying strongly according to the local magnetic-field configuration. In the plane normal to the magnetic field, the steep pedestal electron temperature gradient gives rise to anisotropic turbulence with a radial (normal) wavelength much shorter than in the binormal direction. In the parallel direction, the location and parallel extent of the turbulence are determined by the variation in the magnetic drifts and finite-Larmor-radius (FLR) effects. The magnetic drift and FLR topographies have a perpendicular-wavelength dependence, which permits turbulence intensity maxima near the flux-surface top and bottom at longer binormal scales, but constrains turbulence to the outboard midplane at shorter electron-gyroradius binormal scales. Our simulations show that long-wavelength ETG turbulence does not transport heat efficiently, and significantly decreases overall ETG transport—in our case by ∼40%—through multiscale interactions.</jats:p>

Strong Constraints on Neutrino Nonstandard Interactions from TeV-Scale ν_{μ} Disappearance at IceCube.

Physical review letters 129:1 (2022) 011804

Authors:

R Abbasi, M Ackermann, J Adams, JA Aguilar, M Ahlers, M Ahrens, JM Alameddine, C Alispach, AA Alves, NM Amin, K Andeen, T Anderson, G Anton, C Argüelles, Y Ashida, S Axani, X Bai, A Balagopal, A Barbano, SW Barwick, B Bastian, V Basu, S Baur, R Bay, JJ Beatty, K-H Becker, J Becker Tjus, C Bellenghi, S Benda, S BenZvi, D Berley, E Bernardini, DZ Besson, G Binder, D Bindig, E Blaufuss, S Blot, M Boddenberg, F Bontempo, J Borowka, S Böser, O Botner, J Böttcher, E Bourbeau, F Bradascio, J Braun, B Brinson, S Bron, J Brostean-Kaiser, S Browne, A Burgman, RT Burley, RS Busse, MA Campana, EG Carnie-Bronca, C Chen, Z Chen, D Chirkin, K Choi, BA Clark, K Clark, L Classen, A Coleman, GH Collin, JM Conrad, P Coppin, P Correa, DF Cowen, R Cross, C Dappen, P Dave, C De Clercq, JJ DeLaunay, D Delgado López, H Dembinski, K Deoskar, A Desai, P Desiati, KD de Vries, G de Wasseige, M de With, T DeYoung, A Diaz, JC Díaz-Vélez, M Dittmer, H Dujmovic, M Dunkman, MA DuVernois, E Dvorak, T Ehrhardt, P Eller, R Engel, H Erpenbeck, J Evans, PA Evenson, KL Fan, AR Fazely, A Fedynitch, N Feigl, S Fiedlschuster, AT Fienberg, K Filimonov, C Finley, L Fischer, D Fox, A Franckowiak, E Friedman, A Fritz, P Fürst, TK Gaisser, J Gallagher, E Ganster, A Garcia, S Garrappa, L Gerhardt, A Ghadimi, C Glaser, T Glauch, T Glüsenkamp, JG Gonzalez, S Goswami, D Grant, T Grégoire, S Griswold, C Günther, P Gutjahr, C Haack, A Hallgren, R Halliday, L Halve, F Halzen, M Ha Minh, K Hanson, J Hardin, AA Harnisch, A Haungs, D Hebecker, K Helbing, F Henningsen, EC Hettinger, S Hickford, J Hignight, C Hill, GC Hill, KD Hoffman, R Hoffmann, K Hoshina, F Huang, M Huber, T Huber, K Hultqvist, M Hünnefeld, R Hussain, K Hymon, S In, N Iovine, A Ishihara, M Jansson, GS Japaridze, M Jeong, M Jin, BJP Jones, D Kang, W Kang, X Kang, A Kappes, D Kappesser, L Kardum, T Karg, M Karl, A Karle, U Katz, M Kauer, M Kellermann, JL Kelley, A Kheirandish, K Kin, T Kintscher, J Kiryluk, SR Klein, R Koirala, H Kolanoski, T Kontrimas, L Köpke, C Kopper, S Kopper, DJ Koskinen, P Koundal, M Kovacevich, M Kowalski, T Kozynets, E Kun, N Kurahashi, N Lad, C Lagunas Gualda, JL Lanfranchi, MJ Larson, F Lauber, JP Lazar, JW Lee, K Leonard, A Leszczyńska, Y Li, M Lincetto, QR Liu, M Liubarska, E Lohfink, CJ Lozano Mariscal, L Lu, F Lucarelli, A Ludwig, W Luszczak, Y Lyu, WY Ma, J Madsen, KBM Mahn, Y Makino, S Mancina, IC Mariş, I Martinez-Soler, R Maruyama, S McCarthy, T McElroy, F McNally, JV Mead, K Meagher, S Mechbal, A Medina, M Meier, S Meighen-Berger, J Micallef, D Mockler, T Montaruli, RW Moore, R Morse, M Moulai, R Naab, R Nagai, U Naumann, J Necker, LV Nguyễn, H Niederhausen, MU Nisa, SC Nowicki, A Obertacke Pollmann, M Oehler, B Oeyen, A Olivas, E O'Sullivan, H Pandya, DV Pankova, N Park, GK Parker, EN Paudel, L Paul, C Pérez de Los Heros, L Peters, J Peterson, S Philippen, S Pieper, M Pittermann, A Pizzuto, M Plum, Y Popovych, A Porcelli, M Prado Rodriguez, PB Price, B Pries, GT Przybylski, C Raab, J Rack-Helleis, A Raissi, M Rameez, K Rawlins, IC Rea, Z Rechav, A Rehman, P Reichherzer, R Reimann, G Renzi, E Resconi, S Reusch, W Rhode, M Richman, B Riedel, EJ Roberts, S Robertson, G Roellinghoff, M Rongen, C Rott, T Ruhe, D Ryckbosch, D Rysewyk Cantu, I Safa, J Saffer, SE Sanchez Herrera, A Sandrock, M Santander, S Sarkar, S Sarkar, K Satalecka, M Schaufel, H Schieler, S Schindler, T Schmidt, A Schneider, J Schneider, FG Schröder, L Schumacher, G Schwefer, S Sclafani, D Seckel, S Seunarine, A Sharma, S Shefali, N Shimizu, M Silva, B Skrzypek, B Smithers, R Snihur, J Soedingrekso, D Soldin, C Spannfellner, GM Spiczak, C Spiering, J Stachurska, M Stamatikos, T Stanev, R Stein, J Stettner, T Stezelberger, T Stürwald, T Stuttard, GW Sullivan, I Taboada, S Ter-Antonyan, J Thwaites, S Tilav, F Tischbein, K Tollefson, C Tönnis, S Toscano, D Tosi, A Trettin, M Tselengidou, CF Tung, A Turcati, R Turcotte, CF Turley, JP Twagirayezu, B Ty, MA Unland Elorrieta, N Valtonen-Mattila, J Vandenbroucke, N van Eijndhoven, D Vannerom, J van Santen, J Veitch-Michaelis, S Verpoest, C Walck, W Wang, TB Watson, C Weaver, P Weigel, A Weindl, MJ Weiss, J Weldert, C Wendt, J Werthebach, M Weyrauch, N Whitehorn, CH Wiebusch, DR Williams, M Wolf, K Woschnagg, G Wrede, J Wulff, XW Xu, JP Yanez, E Yildizci, S Yoshida, S Yu, T Yuan, Z Zhang, P Zhelnin, IceCube Collaboration

Abstract:

We report a search for nonstandard neutrino interactions (NSI) using eight years of TeV-scale atmospheric muon neutrino data from the IceCube Neutrino Observatory. By reconstructing incident energies and zenith angles for atmospheric neutrino events, this analysis presents unified confidence intervals for the NSI parameter ε_{μτ}. The best-fit value is consistent with no NSI at a p value of 25.2%. With a 90% confidence interval of -0.0041≤ε_{μτ}≤0.0031 along the real axis and similar strength in the complex plane, this result is the strongest constraint on any NSI parameter from any oscillation channel to date.