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A comparison of maps and power spectra determined from south pole telescope and planck data

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arXiv 2017年

作者： Hou, Z. Aylor, K. Benson, B.A. Bleem, L.E. Carlstrom, J.E. Chang, C.L. Cho, H-M. Chown, R. Crawford, T.M. Crites, A.T. de Haan, T. Dobbs, M.A. Everett, W.B. Follin, B. George, E.M. Halverson, N.W. Harrington, N.L. Holder, G.P. Holzapfel, W.L. Hrubes, J.D. Keisler, R. Knox, L. Lee, A.T. Leitch, E.M. Luong-Van, D. Marrone, D.P. McMahon, J.J. Meyer, S.S. Millea, M. Mocanu, L.M. Mohr, J.J. Natoli, T. Omori, Y. Padin, S. Pryke, C. Reichardt, C.L. Ruhl, J.E. Sayre, J.T. Schaffer, K.K. Shirokoff, E. Staniszewski, Z. Stark, A.A. Story, K.T. Vanderlinde, K. Vieira, J.D. Williamson, R. Kavli Institute for Cosmological Physics University of Chicago ChicagoIL60637 United States Department of Astronomy and Astrophysics University of Chicago ChicagoIL60637 United States Department of Physics University of California DavisCA95616 United States Fermi National Accelerator Laboratory MS209 P.O. Box 500 BataviaIL60510 United States High Energy Physics Division Argonne National Laboratory ArgonneIL60439 United States Department of Physics University of Chicago ChicagoIL60637 United States Enrico Fermi Institute University of Chicago ChicagoIL60637 United States SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo ParkCA94025 United States Department of Physics McGill Space Institute McGill University MontrealQCH3A 2T8 Canada California Institute of Technology PasadenaCA91125 United States Department of Physics University of California BerkeleyCA94720 United States Canadian Institute for Advanced Research CIFAR Program in Cosmology and Gravity TorontoONM5G1Z8 Canada Center for Astrophysics and Space Astronomy Department of Astrophysical and Planetary Sciences University of Colorado BoulderCO80309 United States European Southern Observatory Karl-Schwarzschild-Strabe 2 Garching85748 Germany Department of Physics University of Colorado BoulderCO80309 United States Astronomy Department University of Illinois at Urbana-Champaign 1002 W. Green Street UrbanaIL61801 United States Department of Physics University of Illinois Urbana-Champaign 1110 W. Green Street UrbanaIL61801 United States University of Chicago ChicagoIL60637 United States Kavli Institute for Particle Astrophysics and Cosmology Stanford University 452 Lomita Mall StanfordCA94305 United States Physics Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Steward Observatory University of Arizona 933 North Cherry Avenue TucsonAZ85721 United States Department of Physics University of Michigan Ann ArborMI481

We study the consistency of 150 GHz data from the South Pole Telescope (SPT) and 143 GHz data from the Planck satellite over the patch of sky covered by the SPT-SZ survey. We rst visually compare the maps and find that the residuals appear consistent with noise after accounting for dierences in angular resolution and filtering. We then calculate (1) the cross-spectrum between two independent halves of SPT data, (2) the cross-spectrum between two independent halves of Planck data, and (3) the cross-spectrum between SPT and Planck data. We find the three cross-spectra are well-fit (PTE = 0.30) by the null hypothesis in which both experiments have measured the same sky map up to a single free calibration parameter|i.e., we find no evidence for systematic errors in either data set. As a by-product, we improve the precision of the SPT calibration by nearly an order of magnitude, from 2.6% to 0.3% in power. Finally, we compare all three cross-spectra to the full-sky Planck power spectrum and find marginal evidence for differences between the power spectra from the SPT-SZ footprint and the full sky. We model these differences as a power law in spherical harmonic multipole number. The best-fit value of this tilt is consistent among the three cross-spectra in the SPT-SZ footprint, implying that the source of this tilt is a sample variance uctuation in the SPT-SZ region relative to the full sky. The consistency of cosmological parameters derived from these datasets is discussed in a companion paper. Copyright © 2017, The Authors. All rights reserved.

关键词： Telescopes

EEG activation response under different neurohumoral states

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Human Physiology 2014年第4期40卷 375-382页

作者： Bazanova, O.M. Kuzminova, O.I. Nikolenko, E.D. Petrova, S.E. Russian Institute for Advanced Study in Humanities and Technology Sholokhov Moscow State University for the Humanities Moscow 109240 Russian Federation Institute of Molecular Biology and Biophysics Siberian Branch Russian Academy of Medical Sciences Novosibirsk 630117 Russian Federation Research Center for Clinical and Experimental Medicine Siberian Branch Russian Academy of Medical Sciences Novosibirsk 630117 Russian Federation

In order to determine under which neurohumoral conditions the response to usual opening of the eyes stimulates the Berger effect, the electroencephalographic, electrocardiographic, and electromyographic responses to eyes opening have been recorded simultaneously with the psychometric indices of emotional tension and cognitive performance in 59 healthy women aged 18-27 years every two or three days during one or two menstrual cycles determined according the progesterone level in the morning. For excluding the influence of the Novelty factor, the monitoring began at the menstrual phase of the cycle in 29 women and at the luteal phase in the other 30 women. A single examination has been performed in a separate group of 30 women to study the relationship of these parameters with the current progesterone and cortisol levels in saliva. Two-factor ANOVA has shown that the magnitude of amplitude suppression and the bandwidth of the low-frequency α EEG range in the follicular phase of the menstrual cycle are greater than in the luteal one and depend on the Novelty factor. The indices of the Berger effect of the upper-frequency α range do not depend on the neurohumoral state or the Novelty factor. The amplitude suppression and the bandwidth of the lowfrequency α range alone are predictors of the activation in the response to eyes opening because the changes are unidirectional and are interrelated with the autonomic and hormonal characteristics of the activation. It has been demonstrated that eyes opening is a stimulus for the activation only in the neurohumoral state corresponding to the follicular phase of the menstrual cycle. This study has established the dependence of the central and autonomic activation on the individual α frequency EEG profile and the neurohumoral state. © 2014 Pleiades Publishing, Inc.

关键词： activation eyes opening individual alpha bandwidth individual α-peak frequency magnitude and duration of EEG α-wave suppression neurohumoral state

A comparison of cosmological parameters determined from cmb temperature power spectra from the south pole telescope and the planck satellite

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arXiv 2017年

作者： Aylor, K. Hou, Z. Knox, L. Story, K.T. Benson, B.A. Bleem, L.E. Carlstrom, J.E. Chang, C.L. Cho, H.-M. Chown, R. Crawford, T.M. Crites, A.T. de Haan, T. Dobbs, M.A. Everett, W.B. George, E.M. Halverson, N.W. Harrington, N.L. Holder, G.P. Holzapfel, W.L. Hrubes, J.D. Keisler, R. Lee, A.T. Leitch, E.M. Luong-Van, D. Marrone, D.P. McMahon, J.J. Meyer, S.S. Millea, M. Mocanu, L.M. Mohr, J.J. Natoli, T. Omori, Y. Padin, S. Pryke, C. Reichardt, C.L. Ruhl, J.E. Sayre, J.T. Schaffer, K.K. Shirokoff, E. Staniszewski, Z. Stark, A.A. Vanderlinde, K. Vieira, J.D. Williamson, R. Department of Physics University of California DavisCA95616 United States Kavli Institute for Cosmological Physics University of Chicago ChicagoIL60637 United States Department of Astronomy and Astrophysics University of Chicago ChicagoIL60637 United States Kavli Institute for Particle Astrophysics and Cosmology Stanford University 452 Lomita Mall StanfordCA94305 United States Dept. of Physics Stanford University 382 Via Pueblo Mall StanfordCA94305 United States Fermi National Accelerator Laboratory MS209 P.O. Box 500 BataviaIL60510 United States High Energy Physics Division Argonne National Laboratory ArgonneIL60439 United States Department of Physics University of Chicago ChicagoIL60637 United States Enrico Fermi Institute University of Chicago ChicagoIL60637 United States SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo ParkCA94025 United States Department of Physics and McGill Space Institute McGill University MontrealQCH3A 2T8 Canada California Institute of Technology PasadenaCA91125 United States Department of Physics University of California BerkeleyCA94720 United States Canadian Institute for Advanced Research CIFAR Program in Cosmology and Gravity TorontoONM5G 1Z8 Canada Center for Astrophysics and Space Astronomy Department of Astrophysical and Planetary Sciences University of Colorado BoulderCO80309 United States European Southern Observatory Karl-Schwarzschild-Straße 2 Garching85748 Germany Department of Physics University of Colorado BoulderCO80309 United States Astronomy Department University of Illinois at Urbana-Champaign 1002 W. Green Street UrbanaIL61801 United States Department of Physics University of Illinois Urbana-Champaign 1110 W. Green Street UrbanaIL61801 United States University of Chicago ChicagoIL60637 United States Physics Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Steward Observatory University of Arizona 933 North Cherry Avenu

The Planck cosmic microwave background (CMB) temperature data are best fit with a ΛCDM model that is in mild tension with constraints from other cosmological probes. The South Pole Telescope (SPT) 2540 deg2 SPT-SZ survey offers measurements on sub-degree angular scales (multipoles 650 ≤ ` ≤ 2500) with sufficient precision to use as an independent check of the Planck data. Here we build on the recent joint analysis of the SPT-SZ and Planck data in Hou et al. (2017) by comparing ΛCDM parameter estimates using the temperature power spectrum from both data sets in the SPT-SZ survey region. We also restrict the multipole range used in parameter fitting to focus on modes measured well by both SPT and Planck, thereby greatly reducing sample variance as a driver of parameter differences and creating a stringent test for systematic errors. We find no evidence of systematic errors from such tests. When we expand the maximum multipole of SPT data used, we see low-significance shifts in the angular scale of the sound horizon and the physical baryon and cold dark matter densities, with a resulting trend to higher Hubble constant. When we compare SPT and Planck data on the SPT-SZ sky patch to Planck full-sky data but keep the multipole range restricted, we find differences in the parameters ns and Ase−2τ. We perform further checks, investigating instrumental effects and modeling assumptions, and we find no evidence that the effects investigated are responsible for any of the parameter shifts. Taken together, these tests reveal no evidence for systematic errors in SPT or Planck data in the overlapping sky coverage and multipole range and, at most, weak evidence for a breakdown of ΛCDM or systematic errors influencing either the Planck data outside the SPT-SZ survey area or the SPT data at ` > 2000. Copyright © 2017, The Authors. All rights reserved.

关键词： Telescopes

CMB polarization B-mode delensing with SPTpol and Herschel

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arXiv 2017年

作者： Manzotti, A. Story, K.T. Wu, W.L.K. Austermann, J.E. Beall, J.A. Bender, A.N. Benson, B.A. Bleem, L.E. Bock, J.J. Carlstrom, J.E. Chang, C.L. Chiang, H.C. Cho, H.-M. Citron, R. Conley, A. Crawford, T.M. Crites, A.T. de Haan, T. Dobbs, M.A. Dodelson, S. Everett, W. Gallicchio, J. George, E.M. Gilbert, A. Halverson, N.W. Harrington, N. Henning, J.W. Hilton, G.C. Holder, G.P. Holzapfel, W.L. Hoover, S. Hou, Z. Hrubes, J.D. Huang, N. Hubmayr, J. Irwin, K.D. Keisler, R. Knox, L. Lee, A.T. Leitch, E.M. Li, D. McMahon, J.J. Meyer, S.S. Mocanu, L.M. Natoli, T. Nibarger, J.P. Novosad, V. Padin, S. Pryke, C. Reichardt, C.L. Ruhl, J.E. Saliwanchik, B.R. Sayre, J.T. Schaffer, K.K. Smecher, G. Stark, A.A. Vanderlinde, K. Vieira, J.D. Viero, M.P. Wang, G. Whitehorn, N. Yefremenko, V. Zemcov, M. Kavli Institute for Cosmological Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Astronomy and Astrophysics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Kavli Institute for Particle Astrophysics and Cosmology Stanford University 452 Lomita Mall StanfordCA94305 United States Dept. of Physics Stanford University 382 Via Pueblo Mall StanfordCA94305 United States Department of Physics University of California BerkeleyCA94720 United States NIST Quantum Devices Group 325 Broadway Mailcode 817.03 BoulderCO80305 United States High Energy Physics Division Argonne National Laboratory 9700 S. Cass Avenue ArgonneIL60439 United States Fermi National Accelerator Laboratory MS209 P.O. Box 500 BataviaIL60510 United States California Institute of Technology MS 367-17 1200 E. California Blvd. PasadenaCA91125 United States Jet Propulsion Laboratory PasadenaCA91109 United States Department of Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Enrico Fermi Institute University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States School of Mathematics Statistics & Computer Science University of KwaZulu-Natal Durban South Africa SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo ParkCA94025 United States Department of Physics McGill University 3600 Rue University MontrealQCH3A 2T8 Canada Canadian Institute for Advanced Research CIFAR Program in Cosmology and Gravity TorontoONM5G 1Z8 Canada Department of Astrophysical and Planetary Sciences University of Colorado BoulderCO80309 United States Harvey Mudd College 301 Platt Blvd. ClaremontCA91711 United States Department of Physics University of Colorado BoulderCO80309 United States Astronomy Department University of Illinois at Urbana-Champaign 1002 W. Green Street UrbanaIL61801 United States Department of Physics University of Illinois Urbana-Champ

We present a demonstration of delensing the observed cosmic microwave background (CMB) B-mode polarization anisotropy. This process of reducing the gravitational-lensing generated B-mode component will become increasingly important for improving searches for the B modes produced by primordial gravitational waves. In this work, we delens B-mode maps constructed from multi-frequency SPTpol observations of a 90 deg2 patch of sky by subtracting a B-mode template constructed from two inputs: SPTpol E-mode maps and a lensing potential map estimated from the Herschel 500 µm map of the CIB. We find that our delensing procedure reduces the measured B-mode power spectrum by 28% in the multipole range 300 Copyright © 2017, The Authors. All rights reserved.

关键词： Cosmology

Black hole-neutron star binary merger: Dependence on black hole spin orientation and equation of state

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Physical Review D 2015年第2期92卷 024014-024014页

作者： Kyohei Kawaguchi Koutarou Kyutoku Hiroyuki Nakano Hirotada Okawa Masaru Shibata Keisuke Taniguchi Yukawa Institute for Theoretical Physics Kyoto University Kyoto 606-8502 Japan Interdisciplinary Theoretical Science (iTHES) Research Group RIKEN Wako Saitama 351-0198 Japan Department of Physics Kyoto University Kyoto 606-8502 Japan Center for Computational Relativity and Gravitation and School of Mathematical Sciences Rochester Institute of Technology 85 Lomb Memorial Drive Rochester New York 14623 USA Advanced Research Institute for Science and Engineering Waseda University 3-4-1 Okubo Shinjuku Tokyo 169-8555 Japan Department of Physics University of the Ryukyus Nishihara Okinawa 903-0213 Japan Graduate School of Arts and Sciences University of Tokyo Komaba Meguro Tokyo 153-8902 Japan

We systematically performed numerical-relativity simulations for black hole-neutron star (BH-NS) binary mergers with a variety of the BH spin orientation and nuclear-theory-based equations of state (EOS) of the NS. The initial misalignment angles of the BH spin measured from the direction of the orbital angular momentum are chosen in the range of itilt,0≈30°−90°. We employed four models of nuclear-theory-based zero-temperature EOS for the NS in which the compactness of the NS is in the range of C=MNS/RNS=0.138−0.180, where MNS and RNS are the mass and the radius of the NS, respectively. The mass ratio of the BH to the NS, Q=MBH/MNS, and the dimensionless spin parameter of the BH, χ, are chosen to be Q=5 and χ=0.75, together with MNS=1.35M⊙ so that the BH spin misalignment has a significant effect on tidal disruption of the NS. We obtain the following results: (i) The inclination angles of itilt,0<70° and itilt,0<50° are required for the formation of a remnant disk with its mass larger than 0.1M⊙ for the cases C=0.140 and C=0.160, respectively, while the disk mass is always smaller than 0.1M⊙ for C≳0.175. The ejecta with its mass larger than 0.01M⊙ is obtained for itilt,0<85° with C=0.140, for itilt,0<65° with C=0.160, and for itilt,0<30° with C=0.175. (ii) The rotational axis of the dense part of the remnant disk with its rest-mass density larger than 109 g/cm3 is approximately aligned with the remnant BH spin for itilt,0≈30°. On the other hand, the disk axis is misaligned initially with ∼30° for itilt,0≈60°, and the alignment with the remnant BH spin is achieved at ∼50–60 ms after the onset of merger. The accretion time scale of the remnant disk is typically ∼100 ms and depends only weakly on the misalignment angle and the EOS. (iii) The ejecta velocity is typically ∼0.2–0.3c and depends only weakly on the misalignment angle and the EOS of the NS, while the morphology of the ejecta depends on its mass. (iv) The gravitational-wave spectra contains the information

关键词： Black holes (Astronomy) Neutron stars Equations of state

Measurements of the temperature and E-mode polarization of the cmb from 500 square degrees of sptpol data

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arXiv 2017年

作者： Henning, J.W. Sayre, J.T. Reichardt, C.L. Ade, P.A.R. Anderson, A.J. Austermann, J.E. Beall, J.A. Bender, A.N. Benson, B.A. Bleem, L.E. Carlstrom, J.E. Chang, C.L. Chiang, H.C. Cho, H.-M. Citron, R. Corbett Moran, C. Crawford, T.M. Crites, A.T. de Haan, T. Dobbs, M.A. Everett, W. Gallicchio, J. George, E.M. Gilbert, A. Halverson, N.W. Harrington, N. Hilton, G.C. Holder, G.P. Holzapfel, W.L. Hoover, S. Hou, Z. Hrubes, J.D. Huang, N. Hubmayr, J. Irwin, K.D. Keisler, R. Knox, L. Lee, A.T. Leitch, E.M. Li, D. Lowitz, A. Manzotti, A. McMahon, J.J. Meyer, S.S. Mocanu, L. Montgomery, J. Nadolski, A. Natoli, T. Nibarger, J.P. Novosad, V. Padin, S. Pryke, C. Ruhl, J.E. Saliwanchik, B.R. Schaffer, K.K. Sievers, C. Smecher, G. Stark, A.A. Story, K.T. Tucker, C. Vanderlinde, K. Veach, T. Vieira, J.D. Wang, G. Whitehorn, N. Wu, W.L.K. Yefremenko, V. Kavli Institute for Cosmological Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Department of Astronomy and Astrophysics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Center for Astrophysics and Space Astronomy Department of Astrophysical and Planetary Sciences University of Colorado BoulderCO80309 United States School of Physics University of Melbourne ParkvilleVIC3010 Australia School of Physics and Astronomy Cardiff University CF24 3AA United Kingdom Fermi National Accelerator Laboratory MS209 P.O. Box 500 BataviaIL60510 United States NIST Quantum Sensors Group 325 Broadway Mailcode 687.08 BoulderCO80305 United States High Energy Physics Division Argonne National Laboratory 9700 S. Cass Avenue ArgonneIL60439 United States Department of Physics University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States Enrico Fermi Institute University of Chicago 5640 South Ellis Avenue ChicagoIL60637 United States School of Mathematics Statistics & Computer Science University of KwaZulu-Natal Durban South Africa SLAC National Accelerator Laboratory 2575 Sand Hill Road Menlo ParkCA94025 United States TAPIR Walter Burke Institute for Theoretical Physics California Institute of Technology 1200 E California Blvd PasadenaCA91125 United States California Institute of Technology MS 249-17 1216 E. California Blvd. PasadenaCA91125 United States Department of Physics University of California BerkeleyCA94720 United States Department of Physics McGill University 3600 Rue University MontrealQCH3A 2T8 Canada Canadian Institute for Advanced Research CIFAR Program in Cosmology and Gravity TorontoONM5G 1Z8 Canada Harvey Mudd College 301 Platt Blvd. ClaremontCA91711 United States European Southern Observatory Karl-Schwarzschild-Str. 2 Garching85748 Germany Department of Physics University of Colorado BoulderCO80309 United States Astronomy Department University

We present measurements of the E-mode polarization angular auto-power spectrum (EE) and temperature-E-mode cross-power spectrum (TE) of the cosmic microwave background (CMB) using 150 GHz data from three seasons of SPTpol observations. We report the power spectra over the spherical harmonic multipole range 50 1050 and ` > 1475, respectively. The observations cover 500 deg2, a fivefold increase in area compared to previous SPTpol analyses, which increases our sensitivity to the photon diffusion damping tail of the CMB power spectra enabling tighter constraints on ΛCDM model extensions. After masking all sources with unpolarized flux > 50 mJy we place a 95% confidence upper limit on residual polarized point-source power of D` = `(` + 1)C`/2π 2 at ` = 3000, suggesting that the EE damping tail dominates foregrounds to at least ` = 4050 with modest source masking. We find that the SPTpol dataset is in mild tension with the ΛCDM model (2.1 σ), and different data splits prefer parameter values that differ at the ∼ 1 σ level. When fitting SPTpol data at ` 1000 results in a preference for a higher value of the expansion rate (H0 = 71.3 ± 2.1 km s−1Mpc−1 ) and a lower value for present-day density fluctuations (σ8 = 0.77 ± 0.02). Copyright © 2017, The Authors. All rights reserved.

关键词： Power spectrum

Microwave Down-Conversion with an Impedance-Matched Λ System in Driven Circuit QED

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Physical Review Letters 2014年第6期113卷 063604-063604页

作者： K. Inomata K. Koshino Z. R. Lin W. D. Oliver J. S. Tsai Y. Nakamura T. Yamamoto RIKEN Center for Emergent Matter Science (CEMS) Wako Saitama 351-0198 Japan College of Liberal Arts and Sciences Tokyo Medical and Dental University Ichikawa Chiba 272-0827 Japan MIT Lincoln Laboratory 244 Wood Street Lexington Massachusetts 02420 USA NEC Smart Energy Research Laboratories Tsukuba Ibaraki 305-8501 Japan Research Center for Advanced Science and Technology (RCAST) The University of Tokyo Meguro-ku Tokyo 153-8904 Japan

By driving a dispersively coupled qubit-resonator system, we realize an “impedance-matched” Λ system that has two identical radiative decay rates from the top level and interacts with a semi-infinite waveguide. It has been predicted that a photon input from the waveguide deterministically induces a Raman transition in the system and switches its electronic state. We confirm this through microwave response to a continuous probe field, observing near-perfect (99.7%) extinction of the reflection and highly efficient (74%) frequency down-conversion. These proof-of-principle results lead to deterministic quantum gates between material qubits and microwave photons and open the possibility for scalable quantum networks interconnected with waveguide photons.

关键词： IMPEDANCE spectroscopy QUBITS RESONATORS RAMAN effect PHOTONS

A comparison of actual and artifactual features based on fractal analyses: Resting-State MEG data

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Advances in Intelligent Systems and Computing

Advances in Intelligent Systems and Computing 2013年 212卷 1257-1265页

作者： Phothisonothai, Montri Tsubomi, Hiroyuki Kondo, Aki Yoshimura, Yuko Kikuchi, Mitsuru Minabe, Yoshio Watanabe, Katsumi Research Center for Advanced Science and Technology The University of Tokyo Tokyo 153-8904 Japan Faculty of Humanities The University of Toyama Toyama 930-8555 Japan Research Center for Child Mental Development Graduate School of Medical Science Kanazawa University Kanazawa 920-8641 Japan

ISBN: (纸本)9783642375019

Future standardized system for distinguishing actual and artifactual magnetoencephalogram (MEG) data is an essential tool. In this paper, we proposed the quantitative parameters based on fractal dimension (FD) analyses in which the FD may convey different features before and after artifact removal. The six FD algorithms based on time-series computation, namely, box-counting method (BCM), variance fractal dimension (VFD), Higuchi's method (HM), Kazt's method (KM), detrended fluctuation analysis (DFA), and modified zero-crossing rate (MZCR) were compared. These approaches measure nonlinear-behavioral responses in the resting-state MEG data. Experimental results showed that the FD value of actual MEG was increased statistically in comparison with the artifactual MEG. The DFA and the HM present a best performance for analyzing simulated data and resting-state MEG data, respectively. © Springer-Verlag Berlin Heidelberg 2013.

关键词： Fractal dimension

Information slows down hierarchy growth

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Physical Review E 2014年第6期89卷 062810-062810页

作者： Agnieszka Czaplicka Krzysztof Suchecki Borja Miñano Miquel Trias Janusz A. Hołyst Faculty of Physics Center of Excellence for Complex Systems Research Warsaw University of Technology Koszykowa 75 PL-00-662 Warsaw Poland Institute for Applied Computing with Community Code (IAC3) Universitat de les Illes Balears. Cra. Valldemossa km 7.5 E-07122 Palma Spain Netherlands Institute for Advanced Study in the Humanities and Social Sciences Meijboomlaan 1 2242 PR Wassenaar The Netherlands

We consider models of growing multilevel systems wherein the growth process is driven by rules of tournament selection. A system can be conceived as an evolving tree with a new node being attached to a contestant node at the best hierarchy level (a level nearest to the tree root). The proposed evolution reflects limited information on system properties available to new nodes. It can also be expressed in terms of population dynamics. Two models are considered: a constant tournament (CT) model wherein the number of tournament participants is constant throughout system evolution, and a proportional tournament (PT) model where this number increases proportionally to the growing size of the system itself. The results of analytical calculations based on a rate equation fit well to numerical simulations for both models. In the CT model all hierarchy levels emerge, but the birth time of a consecutive hierarchy level increases exponentially or faster for each new level. The number of nodes at the first hierarchy level grows logarithmically in time, while the size of the last, “worst” hierarchy level oscillates quasi-log-periodically. In the PT model, the occupations of the first two hierarchy levels increase linearly, but worse hierarchy levels either do not emerge at all or appear only by chance in the early stage of system evolution to further stop growing at all. The results allow us to conclude that information available to each new node in tournament dynamics restrains the emergence of new hierarchy levels and that it is the absolute amount of information, not relative, which governs such behavior.

关键词： INFORMATION networks HIERARCHIES INFORMATION modeling COMPUTER simulation LOGARITHMS