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Diagnostic pathology 2023年第1期18卷 130页

作者： Anna-Leonie Menges Maja Nackenhorst Johannes R Müller Marie-Luise Engl Renate Hegenloh Jaroslav Pelisek Ellen Geibelt Anja Hofmann Christian Reeps Gabor Biro Hans-Henning Eckstein Alexander Zimmermann Derek Magee Martin Falk Nadja Sachs Albert Busch Department for Vascular Surgery University Hospital Zurich Zurich Switzerland. Department of Pathology Medical University of Vienna Vienna Austria. DFG Cluster of Excellence ?Physics of Life? TU Dresden Dresden Germany. Department for Vascular and Endovascular Surgery Klinikum Rechts der Isar Technical University Munich Munich Germany. Light Microscopy Facility Center for Molecular and Cellular Bioengineering (CMCB) Technische Universit?t Dresden Dresden Germany. Department for Visceral- Thoracic and Vascular Surgery Medical Faculty and University Hospital Carl Gustav Carus TUD Dresden University of Technology Fetscherstrasse 74 Dresden Germany. German Center for Cardiovascular Research (DZHK) Munich Heart Alliance Berlin Germany. HeteroGenius Limited Leeds UK. School of Computing University of Leeds Leeds UK. Scientific Visualization Group Department of Science and Technology (ITN) Linköping University Linköping Sweden. Department for Vascular and Endovascular Surgery Klinikum Rechts der Isar Technical University Munich Munich Germany. albert.busch@uniklinikum-dresden.de. Department for Visceral- Thoracic and Vascular Surgery Medical Faculty and University Hospital Carl Gustav Carus TUD Dresden University of Technology Fetscherstrasse 74 Dresden Germany. albert.busch@uniklinikum-dresden.de.

Surrogate models for precessing binary black hole simulations with unequal masses

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arXiv 2019年

作者： Varma, Vijay Field, Scott E. Scheel, Mark A. Blackman, Jonathan Gerosa, Davide Stein, Leo C. Kidder, Lawrence E. Pfeiffer, Harald P. TAPIR 350-17 California Institute of Technology 1200 E California Boulevard PasadenaCA91125 United States Department of Mathematics Center for Scientific Computing and Visualization Research University of Massachusetts DartmouthMA02747 United States School of Physics and Astronomy Institute for Gravitational Wave Astronomy University of Birmingham BirminghamB15 2TT United Kingdom Department of Physics and Astronomy University of Mississippi UniversityMS38677 United States Center for Radiophysics and Space Research Cornell University IthacaNY14853 United States Am Mühlenberg 1 Potsdam14476 Germany

Only numerical relativity simulations can capture the full complexities of binary black hole mergers. These simulations, however, are prohibitively expensive for direct data analysis applications such as parameter estimation. We present two new fast and accurate surrogate models for the outputs of these simulations: the first model, NRSur7dq4, predicts the gravitational waveform and the second model, NRSur7dq4Remnant, predicts the properties of the remnant black hole. These models extend previous 7-dimensional, non-eccentric precessing models to higher mass ratios, and have been trained against 1528 simulations with mass ratios q ≤ 4 and spin magnitudes χ1, χ2 ≤ 0.8, with generic spin directions. The waveform model, NRSur7dq4, which begins about 20 orbits before merger, includes all ` ≤ 4 spin-weighted spherical harmonic modes, as well as the precession frame dynamics and spin evolution of the black holes. The final black hole model, NRSur7dq4Remnant, models the mass, spin, and recoil kick velocity of the remnant black hole. In their training parameter range, both models are shown to be more accurate than existing models by at least an order of magnitude, with errors comparable to the estimated errors in the numerical relativity simulations. We also show that the surrogate models work well even when extrapolated outside their training parameter space range, up to mass ratios q = 6. Copyright © 2019, The Authors. All rights reserved.

关键词： Stars

Relativistic many-body analysis of the electric dipole moment enhancement factor of 210Fr and associated properties

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arXiv 2019年

作者： Shitara, Nanako Sahoo, B.K. Watanabe, T. Das, B.P. Department of Physics School of Science Tokyo Institute of Technology Ookayama Meguro-ku Tokyo152-8550 Japan Atomic Molecular and Optical Physics Division Physical Research Laboratory Navrangpura Ahmedabad380009 India Global Scientific Information and Computing Center Tokyo Institute of Technology Ookayama Meguro-ku Tokyo152-8550 Japan

The relativistic coupled-cluster (RCC) method is a powerful many-body method, particularly in the evaluation of electronic wave functions of heavy atoms and molecules, and can be used to calculate various atomic and molecular properties. One such atomic property is the enhancement factor (R) of the atomic electric dipole moment (EDM) due to an electron EDM needed in electron EDM searches. The EDM of the electron is a sensitive probe of CP-violation, and its search could provide insights into new physics beyond the Standard Model, as well as open questions in cosmology. Electron EDM searches using atoms require the theoretical evaluation of R to provide an upper limit for the magnitude of the electron EDM. In this work, we calculate R of 210Fr in the ground state using an improved RCC method, and perform an analysis on the many-body processes occurring within the system. The RCC method allows one to capture the effects of both the electromagnetic interaction and P- and T-violating interactions, and our work develops this method beyond what had been implemented in the previous works. We also perform calculations of hyperfine structure constants, electric dipole transition matrix elements, and excitation energies, to assess the accuracy of R and the success of our improved method. Finally, we present calculations of R with corrections due to Breit interaction effects, approximate quantum electrodynamics (QED) effects, and some leading triple excitation terms added perturbatively, to assess how significantly these terms contribute to the result. We obtain a final value of R = 799, with an estimated 3% error, which is about 11% smaller than a previously reported theoretical calculation. Copyright © 2019, The Authors. All rights reserved.

关键词： Electric dipole moments

The NANOGrav 12.5-year data set: Search for non-Einsteinian polarization modes in the gravitational-wave background

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arXiv 2021年

作者： Arzoumanian, Zaven Baker, Paul T. Blumer, Harsha Bécsy, Bence Brazier, Adam Brook, Paul R. Burke-Spolaor, Sarah Charisi, Maria Chatterjee, Shami Chen, Siyuan Cordes, James M. Cornish, Neil J. Crawford, Fronefield Cromartie, H. Thankful DeCesar, Megan E. DeGan, Dallas M. Demorest, Paul B. Dolch, Timothy Drachler, Brendan Ellis, Justin A. Ferrara, Elizabeth C. Fiore, William Fonseca, Emmanuel Garver-Daniels, Nathan Gentile, Peter A. Good, Deborah C. Hazboun, Jeffrey S. Holgado, A. Miguel Islo, Kristina Jennings, Ross J. Jones, Megan L. Kaiser, Andrew R. Kaplan, David L. Kelley, Luke Zoltan Key, Joey Shapiro Laal, Nima Lam, Michael T. Lazio, T. Joseph W. Lorimer, Duncan R. Liu, Tingting Luo, Jing Lynch, Ryan S. Madison, Dustin R. McEwen, Alexander McLaughlin, Maura A. Mingarelli, Chiara M.F. Ng, Cherry Nice, David J. Olum, Ken D. Pennucci, Timothy T. Pol, Nihan S. Ransom, Scott M. Ray, Paul S. Romano, Joseph D. Sardesai, Shashwat C. Shapiro-Albert, Brent J. Siemens, Xavier Simon, Joseph Siwek, Magdalena S. Spiewak, Renée Stairs, Ingrid H. Stinebring, Daniel R. Stovall, Kevin Sun, Jerry P. Swiggum, Joseph K. Taylor, Stephen R. Turner, Jacob E. Vallisneri, Michele Vigeland, Sarah J. Wahl, Haley M. Witt, Caitlin A. X-Ray Astrophysics Laboratory NASA Goddard Space Flight Center Code 662 GreenbeltMD20771 United States Department of Physics and Astronomy Widener University One University Place ChesterPA19013 United States Department of Physics and Astronomy West Virginia University P.O. Box 6315 MorgantownWV26506 United States Center for Gravitational Waves and Cosmology West Virginia University Chestnut Ridge Research Building MorgantownWV26505 United States Department of Physics Montana State University BozemanMT59717 United States Cornell Center for Astrophysics and Planetary Science Department of Astronomy Cornell University IthacaNY14853 United States Cornell Center for Advanced Computing Cornell University IthacaNY14853 United States CIFAR Azrieli Global Scholars Program CIFAR Toronto Canada Department of Physics and Astronomy Vanderbilt University 2301 Vanderbilt Place NashvilleTN37235 United States Station de Radioastronomie de Nancay Observatoire de Paris Universite PSL CNRS Universite d'Orleans Nancay18330 France FEMTO-ST Institut de Recherche Department of Time and Frequency UBFC CNRS ENSMM Besancon25030 France Laboratoire de Physique et Chimie de l'Environment et de l'Espace LPC2E UMR7328 Universite d'Orleans CNRS Orleans45071 France Department of Physics and Astronomy Franklin & Marshall College P.O. Box 3003 LancasterPA17604 United States Department of Physics Lafayette College EastonPA18042 United States George Mason University FairfaxVA22030 United States U.S. Naval Research Laboratory WashingtonDC20375 United States Department of Physics Oregon State University CorvallisOR97331 United States National Radio Astronomy Observatory 1003 Lopezville Rd. SocorroNM87801 United States Department of Physics Hillsdale College 33 E. College Street HillsdaleMI49242 United States Eureka Scientific Inc. 2452 Delmer Street Suite 100 OaklandCA94602-3017 United States School of Physics and Astronomy Rochester Institu

We search NANOGrav's 12.5-year data set for evidence of a gravitational wave background (GWB) with all the spatial correlations allowed by general metric theories of gravity. We find no substantial evidence in favor of the existence of such correlations in our data. We find that scalar-transverse (ST) correlations yield signal-to-noise ratios and Bayes factors that are higher than quadrupolar (tensor transverse, TT) correlations. Specifically, we find ST correlations with a signal-to-noise ratio of 2.8 that are preferred over TT correlations (Hellings and Downs correlations) with Bayesian odds of about 20:1. However, the significance of ST correlations is reduced dramatically when we include modeling of the Solar System ephemeris systematics and/or remove pulsar J0030+0451 entirely from consideration. Even taking the nominal signal-to-noise ratios at face value, analyses of simulated data sets show that such values are not extremely unlikely to be observed in cases where only the usual TT modes are present in the GWB. In the absence of a detection of any polarization mode of gravity, we place upper limits on their amplitudes for a spectral index of γ = 5 and a reference frequency of fyr = 1yr-1. Among the upper limits for eight general families of metric theories of gravity, we find the values of A95%TT = (9.7±0.4)×10-16 and A95%ST = (1.4±0.03)×10-15 for the family of metric spacetime theories that contain both TT and ST modes. © 2021, CC BY-NC-SA.

关键词： Gravity waves

Searching For Gravitational Waves From Cosmological Phase Transitions With The NANOGrav 12.5-year dataset

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arXiv 2021年

作者： Arzoumanian, Zaven Baker, Paul T. Blumer, Harsha Bécsy, Bence Brazier, Adam Brook, Paul R. Burke-Spolaor, Sarah Charisi, Maria Chatterjee, Shami Chen, Siyuan Cordes, James M. Cornish, Neil J. Crawford, Fronefield Cromartie, H. Thankful DeCesar, Megan E. Demorest, Paul B. Dolch, Timothy Ellis, Justin A. Ferrara, Elizabeth C. Fiore, William Fonseca, Emmanuel Garver-Daniels, Nathan Gentile, Peter A. Good, Deborah C. Hazboun, Jeffrey S. Holgado, A. Miguel Islo, Kristina Jennings, Ross J. Jones, Megan L. Kaiser, Andrew R. Kaplan, David L. Kelley, Luke Zoltan Key, Joey Shapiro Laal, Nima Lam, Michael T. Lazio, T. Joseph W. Lee, Vincent S.H. Lorimer, Duncan R. Luo, Jing Lynch, Ryan S. Madison, Dustin R. McLaughlin, Maura A. Mingarelli, Chiara M.F. Mitridate, Andrea Ng, Cherry Nice, David J. Pennucci, Timothy T. Pol, Nihan S. Ransom, Scott M. Ray, Paul S. Shapiro-Albert, Brent J. Siemens, Xavier Simon, Joseph Spiewak, Renée Stairs, Ingrid H. Stinebring, Daniel R. Stovall, Kevin Sun, Jerry P. Swiggum, Joseph K. Taylor, Stephen R. Turner, Jacob E. Vallisneri, Michele Vigeland, Sarah J. Witt, Caitlin A. Zurek, Kathryn M. X-Ray Astrophysics Laboratory NASA Goddard Space Flight Center Code 662 GreenbeltMD20771 United States Department of Physics and Astronomy Widener University One University Place ChesterPA19013 United States Department of Physics and Astronomy West Virginia University P.O. Box 6315 MorgantownWV26506 United States Center for Gravitational Waves and Cosmology West Virginia University Chestnut Ridge Research Building MorgantownWV26505 United States Department of Physics Montana State University BozemanMT59717 United States Cornell Center for Astrophysics and Planetary Science Department of Astronomy Cornell University IthacaNY14853 United States Cornell Center for Advanced Computing Cornell University IthacaNY14853 United States CIFAR Azrieli Global Scholars Program CIFAR Toronto Canada Department of Physics and Astronomy Vanderbilt University 2301 Vanderbilt Place NashvilleTN37235 United States Station de Radioastronomie de Nancay Observatoire de Paris Universite PSL CNRS Universite d’Orleans Nancay18330 France FEMTO-ST Institut de recherche Department of Time and Frequency UBFC CNRS ENSMM Besancon25030 France Laboratoire de Physique et Chimie de l’Environment et de l’Espace LPC2E UMR7328 Universite d’Orleans CNRS Orleans45071 France Department of Physics and Astronomy Franklin & Marshall College P.O. Box 3003 LancasterPA17604 United States Department of Physics Lafayette College EastonPA18042 United States George Mason University FairfaxVA22030 United States U.S. Naval Research Laboratory WashingtonDC20375 United States National Radio Astronomy Observatory 1003 Lopezville Rd. SocorroNM87801 United States Department of Physics Hillsdale College 33 E. College Street HillsdaleMI49242 United States Eureka Scientific Inc. 2452 Delmer Street Suite 100 OaklandCA94602-3017 United States Infinia ML 202 Rigsbee Avenue DurhamNC27701 United States Department of Astronomy University of Maryland College ParkMD20742

We search for a first-order phase transition gravitational wave signal in 45 pulsars from the NANOGrav 12.5 year dataset. We find that the data can be modeled in terms of a strong first order phase transition taking place at temperatures below the electroweak scale. However, we do not observe any strong preference for a phase-transition interpretation of the signal over the standard astrophysical interpretation in terms of supermassive black holes mergers;but we expect to gain additional discriminating power with future datasets, improving the signal to noise ratio and extending the sensitivity window to lower frequencies. An interesting open question is how well gravitational wave observatories could separate such signals. © 2021, CC BY.

关键词： Gravity waves

Roadmap on quantum nanotechnologies

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arXiv 2021年

作者： Laucht, Arne Hohls, Frank Ubbelohde, Niels Fernando Gonzalez-Zalba, M. Reilly, David J. Stobbe, Søren Schröder, Tim Scarlino, Pasquale Koski, Jonne V. Dzurak, Andrew Yang, Chih-Hwan Yoneda, Jun Kuemmeth, Ferdinand Bluhm, Hendrik Pla, Jarryd Hill, Charles Salfi, Joe Oiwa, Akira Muhonen, Juha T. Verhagen, Ewold LaHaye, M.D. Kim, Hyun Ho Tsen, Adam W. Culcer, Dimitrie Geresdi, Attila Mol, Jan A. Mohan, Varun Jain, Prashant K. Baugh, Jonathan Centre for Quantum Computation and Communication Technology School of Electrical Engineering and Telecommunications UNSW SydneyNSW2052 Australia Physikalisch-Technische Bundesanstalt Braunschweig38116 Germany Quantum Motion Technologies Nexus Discovery Way LeedsLS2 3AA United Kingdom School of Physics University of Sydney SydneyNSW2006 Australia Microsoft Corporation Station Q Sydney University of Sydney SydneyNSW2006 Australia Department of Photonics Engineering DTU Fotonik Technical University of Denmark Building 343 Kgs. LyngbyDK-2800 Denmark Department of Physics Humboldt-Universität zu Berlin Berlin12489 Germany Department of Physics ETH Zürich ZürichCH-8093 Switzerland Niels Bohr Institute University of Copenhagen Copenhagen2100 Denmark JARA-FIT Institute for Quantum Information RWTH Aachen University and Forschungszentrum Jülich Aachen52074 Germany School of Physics University of Melbourne Melbourne Australia Department of Electrical and Computer Engineering The University of British Columbia VancouverBCV6T 1Z4 Canada The Institute of Scientific and Industrial Research Osaka University Ibaraki Osaka567-0047 Japan Center for Quantum Information and Quantum Biology Institute for open and Transdisciplinary Research Initiative Osaka University Osaka560-8531 Japan Center for Nanophotonics AMOLF Amsterdam1098 XG Netherlands School of Physics The University of New South Wales Sydney2052 Australia Australian Research Council Centre of Excellence in Future Low-Energy Electronics Technologies UNSW Node The University of New South Wales Sydney2052 Australia QuTech and Kavli Institute of Nanoscience Delft University of Technology Delft2600 GA Netherlands School of Physics and Astronomy Queen Mary University of London E1 4NS United Kingdom Department of Materials Science and Engineering University of Illinois at Urbana-Champaign UrbanaIL61801 United States Department of Chemistry University of Illinois at Urbana-Champaign Urbana

Quantum phenomena are typically observable at length and time scales smaller than those of our everyday experience, often involving individual particles or excitations. The past few decades have seen a revolution in the ability to structure matter at the nanoscale, and experiments at the single particle level have become commonplace. This has opened wide new avenues for exploring and harnessing quantum mechanical effects in condensed matter. These quantum phenomena, in turn, have the potential to revolutionize the way we communicate, compute and probe the nanoscale world. Here, we review developments in key areas of quantum research in light of the nanotechnologies that enable them, with a view to what the future holds. Materials and devices with nanoscale features are used for quantum metrology and sensing, as building blocks for quantum computing, and as sources and detectors for quantum communication. They enable explorations of quantum behaviour and unconventional states in nano- and opto-mechanical systems, low-dimensional systems, molecular devices, nano-plasmonics, quantum electrodynamics, scanning tunnelling microscopy, and more. This rapidly expanding intersection of nanotechnology and quantum science/technology is mutually beneficial to both fields, laying claim to some of the most exciting scientific leaps of the last decade, with more on the horizon. © 2021, CC BY.

关键词： Quantum computers

On the incorporation of obstacles in a fluid flow problem using a Navier-Stokes-Brinkman penalization approach

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arXiv 2020年

作者： Fuchsberger, Jana Karabelas, Elias Aigner, Philipp Niederer, Steven Plank, Gernot Schima, Heinrich Haase, Gundolf Institute of Mathematics and Scientific Computing University of Graz Heinrichstraße 36 GrazA-8010 Austria Gottfried Schatz Research Center for Cell Signaling Metabolism and Aging Biophysics Medical University of Graz Neue Stiftingtalstraße 6/D04 GrazA-8010 Austria Department of Biomedical Engineering School of Biomedical Engineering & Imaging Sciences King's College London London United Kingdom Center for Medical Physics and Biomedical Engineering Medical University Vienna Währinger Gürtel 18-20 ViennaA-1090 Austria Ludwig Boltzmann Institute for Cardiovascular Research Währinger Guertel 18-20 ViennaA-1090 Austria BioTechMed-Graz Graz Austria

Simulating the interaction of fluids with immersed moving solids is playing an important role for gaining a better quantitative understanding of how fluid dynamics is altered by the presence of obstacles and, vice versa, which forces are exerted on the solids by the moving fluid. Such problems appear in various contexts, ranging from numerous technical applications such as e.g. turbines to medical problems such as the regulation of cardiovascular hemodyamics by valves. Typically, the numerical treatment of such problems is posed within a fluid structure interaction (FSI) framework. General FSI models are able to capture bidirectional interactions, but are challenging to solve and computationally expensive. Simplified methods offer a possible remedy by achieving better computational efficiency to broaden the scope to demanding application problems with focus on understanding the effect of solids on altering fluid dynamics. In this study we report on the development of a novel method for such applications. In our method rigid moving obstacles are incorporated in a fluid dynamics context using concepts from porous media theory. Based on the Navier-Stokes-Brinkman equations which augments the Navier-Stokes equation with a Darcy drag term our method represents solid obstacles as time-varying regions containing a porous medium of vanishing permeability. Numerical stabilization and turbulence modeling is dealt with by using a residual based variational multiscale (RBVMS) formulation. The additional Darcy drag term and its respective stabilization are easily accomodated in any existing finite-element based Navier-Stokes solver. The key advantages of our approach - computational efficiency and ease of implementation - are demonstrated by solving a standard benchmark problem of a rotating blood pump posed by the Food and Drug Administration Agency (FDA). Validity is demonstrated by conducting a mesh convergence study and by comparison against the extensive set of experimental

关键词： Large eddy simulation

Constraining cosmological phase transitions with the Parkes Pulsar Timing Array

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arXiv 2021年

作者： Xue, Xiao Bian, Ligong Shu, Jing Yuan, Qiang Zhu, Xingjiang Bhat, N.D. Ramesh Dai, Shi Feng, Yi Goncharov, Boris Hobbs, George Howard, Eric Manchester, Richard N. Russell, Christopher J. Reardon, Daniel J. Shannon, R.M. Spiewak, Renée Thyagarajan, Nithyanandan Wang, Jingbo CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China School of Physical Sciences University of Chinese Academy of Sciences Beijing100049 China II. Institute of Theoretical Physics Universität Hamburg Hamburg22761 Germany Department of Physics Chongqing University Chongqing401331 China Chongqing Key Laboratory for Strongly Coupled Physics Chongqing401331 China CAS Key Laboratory of Theoretical Physics Insitute of Theoretical Physics Chinese Academy of Sciences Beijing100190 China CAS Center for Excellence in Particle Physics Beijing100049 China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences Hangzhou310024 China Center for High Energy Physics Peking University Beijing100871 China International Center for Theoretical Physics Asia-Pacific Hangzhou Beijing China Key Laboratory of Dark Matter and Space Astronomy Purple Mountain Observatory Chinese Academy of Sciences Nanjing210023 China School of Astronomy and Space Science University of Science and Technology of China Hefei230026 China School of Physics and Astronomy Monash University ClaytonVIC3800 Australia OzGrav: The ARC Centre of Excellence for Gravitational Wave Discovery HawthornVIC3122 Australia Advanced Institute of Natural Sciences Beijing Normal University Zhuhai519087 China International Centre for Radio Astronomy Research Curtin University BentleyWA6102 Australia Western Sydney University Locked Bag 1797 Penrith South DCNSW1797 Australia University of Chinese Academy of Sciences Beijing100049 China CSIRO Astronomy and Space Science P.O. Box 76 EppingNSW1710 Australia Macquarie University Department of Physics and Astronomy SydneyNSW2109 Australia CSIRO Scientific Computing Australian Technology Park Locked Bag 9013 AlexandriaNSW1435 Australia Centre for Astrophysics and Supercomputing Swinburne University of

A cosmological first-order phase transition is expected to produce a stochastic gravitational wave background. If the phase transition temperature is on the MeV scale, the power spectrum of the induced stochastic gravitational waves peaks around nanohertz frequencies, and can thus be probed with high-precision pulsar timing observations. We search for such a stochastic gravitational wave background with the latest data set of the Parkes Pulsar Timing Array. We find no evidence for a Hellings-Downs spatial correlation as expected for a stochastic gravitational wave background. Therefore, we present constraints on first-order phase transition model parameters. Our analysis shows that pulsar timing is particularly sensitive to the low-temperature (T ∼ 1 − 100 MeV) phase transition with a duration (β/H∗)−1 ∼ 10−2 − 10−1 and therefore can be used to constrain the dark and QCD phase transitions. © 2021, CC BY.

关键词： Pulsars

Accurate and efficient cardiac digital twin from surface ECGs: Insights into identifiability of ventricular conduction system

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Medical image analysis 2025年 105卷 103641页

作者： Thomas Grandits Karli Gillette Gernot Plank Simone Pezzuto Department of Mathematics and Scientific Computing University of Graz Heinrichstraße 36 8010 Graz Austria Euler Institute Università della Svizzera italiana Via Buffi 13 6900 Lugano Switzerland. Electronic address: thomas.grandits@uni-graz.at. Gottfried Schatz Research Center: Medical Physics and Biophysics Medical University of Graz Neue Stiftingtalstraße 6 8010 Graz Austria BioTechMed-Graz Mozartgasse 12/II 8010 Graz Austria. Electronic address: karli.gillette@medunigraz.at. BioTechMed-Graz Mozartgasse 12/II 8010 Graz Austria. Electronic address: gernot.plank@medunigraz.at. Euler Institute Università della Svizzera italiana Via Buffi 13 6900 Lugano Switzerland Department of Mathematics University of Trento Via Sommarive 14 38123 Trento Italy. Electronic address: simone.pezzuto@unitn.it.

Digital twins for cardiac electrophysiology are an enabling technology for precision cardiology. Current forward models are advanced enough to simulate the cardiac electric activity under different pathophysiological conditions and accurately replicate clinical signals like torso electrocardiograms (ECGs). In this work, we address the challenge of matching subject-specific QRS complexes using anatomically accurate, physiologically grounded cardiac digital twins. By fitting the initial conditions of a cardiac propagation model, our non-invasive method predicts activation patterns during sinus rhythm. For the first time, we demonstrate that distinct activation maps can generate identical surface ECGs. To address this non-uniqueness, we introduce a physiological prior based on the distribution of Purkinje-muscle junctions. Additionally, we develop a digital twin ensemble for probabilistic inference of cardiac activation. Our approach marks a significant advancement in the calibration of cardiac digital twins and enhances their credibility for clinical application.

关键词： 12 lead ECG Cardiac digital twin Ensemble learning Gradient-based optimization

Bayesian solar wind modeling with pulsar timing arrays

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arXiv 2021年

作者： Hazboun, Jeffrey S. Simon, Joseph Madison, Dustin R. Arzoumanian, Zaven Crowter, Kathryn DeCesar, Megan E. Demorest, Paul B. Dolch, Timothy Ellis, Justin A. Ferdman, Robert D. Ferrara, Elizabeth C. Fonseca, Emmanuel Gentile, Peter A. Jones, Glenn Jones, Megan L. Lam, Michael T. Levin, Lina Lorimer, Duncan R. Lynch, Ryan S. McLaughlin, Maura A. Ng, Cherry Nice, David J. Pennucci, Timothy T. Ransom, Scott M. Ray, Paul S. Spiewak, Renée Stairs, Ingrid H. Stovall, Kevin Swiggum, Joseph K. Zhu, Weiwei Physical Sciences Division University of Washington Bothell 18115 Campus Way NE BothellWA98011 United States Department of Astrophysical and Planetary Sciences University of Colorado BoulderCO80309 United States Department of Physics University of the Pacific 3601 Pacific Avenue StocktonCA95211 United States X-Ray Astrophysics Laboratory NASA Goddard Space Flight Center Code 662 GreenbeltMD20771 United States Department of Physics and Astronomy University of British Columbia 6224 Agricultural Road VancouverBCV6T 1Z1 Canada George Mason University the Naval Research Laboratory WashingtonDC20375 United States National Radio Astronomy Observatory 1003 Lopezville Rd. SocorroNM87801 United States Department of Physics Hillsdale College 33 E. College Street HillsdaleMI49242 United States Eureka Scientific Inc. 2452 Delmer Street Suite 100 OaklandCA94602-3017 United States Infinia ML 202 Rigsbee Avenue DurhamNC27701 United States School of Chemistry University of East Anglia NorwichNR4 7TJ United Kingdom Department of Astronomy University of Maryland College ParkMD20742 United States NASA/GSFC GreenbeltMD20771 United States NASA Goddard Space Flight Center GreenbeltMD20771 United States Department of Physics and Astronomy West Virginia University P.O. Box 6315 MorgantownWV26506 United States Center for Gravitational Waves and Cosmology West Virginia University Chestnut Ridge Research Building MorgantownWV26505 United States Rigetti Computing Inc. 775 Heinz Ave BerkeleyCA94710 United States Columbia Astrophysics Laboratory Columbia University NY10027 United States Center for Gravitation Cosmology and Astrophysics Department of Physics University of Wisconsin-Milwaukee P.O. Box 413 MilwaukeeWI53201 United States School of Physics and Astronomy Rochester Institute of Technology RochesterNY14623 United States Laboratory for Multiwavelength Astrophysics Rochester Institute of Technology RochesterNY14623 United

Using Bayesian analyses we study the solar electron density with the NANOGrav 11-year pulsar timing array (PTA) dataset. Our model of the solar wind is incorporated into a global fit starting from pulse times-of-arrival. We introduce new tools developed for this global fit, including analytic expressions for solar electron column densities and open source models for the solar wind that port into existing PTA software. We perform an ab initio recovery of various solar wind model parameters. We then demonstrate the richness of information about the solar electron density, nE, that can be gleaned from PTA data, including higher order corrections to the simple 1/r2 model associated with a free-streaming wind (which are informative probes of coronal acceleration physics), quarterly binned measurements of nE and a continuous time-varying model for nE spanning approximately one solar cycle period. Finally, we discuss the importance of our model for chromatic noise mitigation in gravitational-wave analyses of pulsar timing data and the potential of developing synergies between sophisticated PTA solar electron density models and those developed by the solar physics community. © 2021, CC BY.

关键词： Timing circuits