Article
Mathematics
Yan Guo, Mahir Hadzic, Juhi Jang
Summary: In this study, Ori and Piran predicted the existence of selfsimilar spacetimes called relativistic Larson-Penston solutions, and provided a mathematical proof for their existence. The proof involved a thorough analysis of nonlinear invariances associated with the dynamical system, the development of a shooting method, and the construction of a maximal analytic extension of the solution. The problem was reformulated in double-null gauge to obtain an asymptotically flat spacetime with an isolated naked singularity.
Article
Mathematics
Igor Rodnianski, Yakov Shlapentokh-Rothman
Summary: This work focuses on the mathematical study of naked singularities for the Einstein vacuum equations in 3 + 1 dimensions. The solutions constructed correspond to the exterior region of a naked singularity. A new type of self-similarity for the Einstein vacuum equations is introduced, along with a new geometric twisting phenomenon that plays a significant role in singularity formation. Prior to this work, examples of naked singularities were limited to specific solutions in different contexts.
ANNALS OF MATHEMATICS
(2023)
Article
Astronomy & Astrophysics
Shahar Hod
Summary: By using sophisticated string theory calculations, Maldacena and Susskind have demonstrated that near-extremal black holes have a finite mass gap above their zero-temperature configurations. This mass gap, characterizing the mass spectra of near-extremal charged Reissner-Nordstrom black holes, can be inferred from a simple semi-classical analysis with epsilon(gap) = h(2)/M-3.
Article
Astronomy & Astrophysics
S. De Gaetano, L. Di Venere, F. Gargano, F. Loparco, L. Lorusso, M. N. Mazziotta, G. Panzarini, R. Pillera, D. Serini
Summary: All known small solar system bodies have diameters ranging from a few meters to a few thousands of kilometers. The collisional evolution of solar system bodies suggests the existence of a larger number of smaller asteroids with diameters down to about 2 meters. This study uses data collected by the Fermi satellite's Large Area Telescope (LAT) to investigate the gamma-ray emission from the ecliptic and constrain the population of small solar system bodies. A model describing the distribution of asteroid sizes is proposed and the LAT data is used to constrain the expected gamma-ray emission and the model itself.
ASTROPHYSICAL JOURNAL
(2023)
Article
Physics, Multidisciplinary
Thomas Speck, Ashreya Jayaram
Summary: This study explores the directed motion of passive bodies in a fluid of active Brownian particles, showing that the forces responsible for this motion can be related to density and current induced by the body but located far away. The force involved in this motion is a combination of dipolar field strength and the generation of nonvanishing vorticity due to particles leaving the boundary. The localized vorticity near the body and areas of changing local curvature allow for the rational design of particle shapes with desired propulsion properties.
PHYSICAL REVIEW LETTERS
(2021)
Article
Astronomy & Astrophysics
Ozay Gurtug, Mustafa Halilsoy, Mert Mangut
Summary: This study investigates the relationship between non-trivial naked singularities with directional behavior in charged and uncharged Zipoy-Voorhees (ZV) spacetimes, known as ? - metrics, and quantum mechanics. The quantum singularity is understood as a non-unique evolution of test quantum wave packets, while the classical singularity is understood as a geodesic incompleteness with respect to a particle probe. The results of rigorous mathematical calculations show that the outermost singularity developed in the charged and uncharged ZV spacetime on the equatorial plane is quantum mechanically singular for all values of the deformation parameter ?, but directional singularities that develop on the symmetry axis are partially healed for a specific range of the parameter ? if the analysis is restricted to the s-wave mode. However, allowing arbitrary modes, classical directional singularities remain quantum singular.
GENERAL RELATIVITY AND GRAVITATION
(2023)
Article
Communication
Svetlana S. Bodrunova, Anna Litvinenko, Kamilla Nigmatullina
Summary: This article examines the self-limitation of journalists in public affairs media in Russia, revealing a significant difference in their understanding of self-censorship compared to Western democracies. Factors such as personal-level ethical decisions and political threats play a significant role in influencing their behavior, with political threats remaining the most dominant external pressure both online and offline. Additionally, personal motives drive decision-making in posting on social networks.
Article
Psychology, Multidisciplinary
Ana Chapman, Silvia Chapman, Stephanie Cosentino
Summary: The manuscript provides a literary analysis of how the novel Infinite Jest by David Foster Wallace portrays a world where oversaturation of external stimulation leads to a disconnection between mind and body, symbolizing a critique of society through the characters' disembodiment and disconnection.
FRONTIERS IN PSYCHOLOGY
(2021)
Article
Chemistry, Analytical
Joonyoung Lee, Jungyeon Ji, Kyuhwan Hyun, Heedae Lee, Yongchai Kwon
Summary: This study proposes a self-powered glucose biosensor that is flexible, disposable, and portable, allowing for quick measurement of glucose concentration with the naked eye. By utilizing the theory of enzymatic biofuel cell, this biosensor operates without the need for additional power supply and equipment to interpret glucose concentration. The biosensor demonstrates the ability to accurately measure glucose concentration even at low ranges, and has strong potential for commercial use as a glucose sensor.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Neurosciences
Lize De Coster, Pablo Sanchez-Herrero, Jorge Lopez-Moreno, Ana Tajadura-Jimenez
Summary: The study explored the impact of body movement dynamics and clothing cues on own-perceived body matching, finding that confidence about dress fit was higher for dynamic avatars. Results also suggested that smaller body/dress sizes were systematically rated higher, and the interplay between body and dress size played a significant role in participants' self-report. The findings provide important insights for research on body perception and bodily awareness, with implications for practical and clinical applications.
FRONTIERS IN HUMAN NEUROSCIENCE
(2021)
Article
Mathematics, Applied
Harold Blum, Yuchen Liu
Summary: In any Q-Gorenstein flat family of klt singularities, normalized volumes are lower semicontinuous with respect to the Zariski topology, and smooth points have the largest normalized volume. Furthermore, K-semistability is a very generic or empty condition in any Q-Gorenstein flat family of log Fano pairs.
JOURNAL OF THE EUROPEAN MATHEMATICAL SOCIETY
(2021)
Article
Physiology
Kamil Michalik, Marcin Smolarek, Bartosz Ochmann, Marek Zaton
Summary: This study aimed to estimate the optimal load and peak power output (PPO) based on a force-velocity test and compare it with the Wingate Anaerobic Test (WAnT). The results showed no difference in optimal load tested at different sprint numbers, but there were significant differences in PPO between the different mathematical models and the WAnT.
FRONTIERS IN PHYSIOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Ang Li, Hongyuan Yang, Dapeng Yang, Jun Lin, Fan Zheng, Huaizhu Zhang, Ruyun Tian
Summary: A fast self-adjusting method based on dynamic force feedback network is proposed for electrochemical seismometers. The dynamic feedback network provides adaptability in complex environments, while the reuse of feedback source offers a low-cost self-testing ability. The method is verified through simulation and prototype development, demonstrating its adaptability and feasibility.
IEEE SENSORS JOURNAL
(2022)
Review
Communication
Alycia Burnett, Devin Knighton, Christopher Wilson
Summary: This study examines the impact of social media on self-censorship and fear of isolation, finding that the majority may remain silent to the hardcore vocal minority. It also explores the influence of political identity and ideology on these factors.
SOCIAL MEDIA + SOCIETY
(2022)
Article
Green & Sustainable Science & Technology
Babak Zolghadr-Asli, Maedeh Enayati, Hamid Reza Pourghasemi, Mojtaba Naghdyzadegan Jahromi, John P. Tiefenbacher
Summary: Changing climate and human interference are causing unprecedented changes in hydro-climatic variables, challenging conventional time-series modeling methods. A case study of Maharlou Lake in Iran demonstrates a framework to capture the dynamic and non-stationary structure of such environments. The results indicate a decline and depletion of the lake, potentially following the tragic fate of similar inland water bodies.
ENVIRONMENT DEVELOPMENT AND SUSTAINABILITY
(2021)
Article
Computer Science, Hardware & Architecture
Gaurav Khanna, Sanjay K. Chaturvedi, Mohamed Othman
Summary: This paper proposes two novel designs of Multistage Interconnection Networks (MINs), which utilize chaining of switches, multiplexers, and demultiplexers for better fault tolerance. Comparing with 19 other MIN layouts, the proposed MINs are shown to be highly competitive in terms of reliability and cost effectiveness.
JOURNAL OF SUPERCOMPUTING
(2023)
Article
Economics
Gaurav Khanna
Summary: The economic consequences of large-scale government investments in education depend on general equilibrium effects in both the labor market and the education sector. I develop a general equilibrium model capturing the consequences of massive countrywide schooling initiatives. Using a regression discontinuity derived from Indian government policy, I provide unbiased estimates of the model's elasticities. The earnings returns to a year of education are 13.4%, and the general equilibrium labor market effects substantially depress returns, by 6.6 percentage points. These general equilibrium effects have distributional consequences across cohorts and skill groups, whereby unskilled workers are better off and skilled workers worse off.
JOURNAL OF POLITICAL ECONOMY
(2023)
Correction
Computer Science, Hardware & Architecture
Gaurav Khanna, Sanjay K. Chaturvedi, Mohamed Othman
JOURNAL OF SUPERCOMPUTING
(2023)
Article
Construction & Building Technology
Vitor E. M. Cardoso, M. Lurdes Simoes, Nuno M. M. Ramos, Ricardo M. S. F. Almeida, Manuela Almeida, Ricardo Mateus
Summary: Assessing individual elements of the air barrier in a building envelope is not feasible in Life Cycle Assessment (LCA), and the study of these solutions is often overlooked due to the complexity of relationships between elements and the minimal impact of these materials in the overall construction or retrofitting works. This study uses LCA and Life Cycle Costing (LCC) to evaluate the viability of two envelope air barrier solutions in dwellings with excessive air change rates and different heating systems. The application of air barrier solutions resulted in significant energy savings, with mechanically fastened air barriers outperforming fluid applied ones in terms of environmental performance and life cycle costs. Dwellings equipped with electric radiators showed the shortest average Energy Payback Period (EPP) and the highest average Reference Service Life (RSL) savings. Based on the analysis, the adoption of mechanically fastened solutions is recommended regardless of the heating system in the dwelling.
ENERGY AND BUILDINGS
(2023)
Article
Astronomy & Astrophysics
Tiago V. Fernandes, David Hilditch, Jose P. S. Lemos, Vitor Cardoso
Summary: A normal mode analysis is performed on Proca fields in the anti-de Sitter (AdS) spacetime, and it is discovered that the equations for the Proca field can be analytically decoupled by changing the basis of the vector spherical harmonics decomposition. The normal modes and frequencies of the Proca equation in the AdS spacetime are then determined analytically. Additionally, it is demonstrated that the Maxwell field can be recovered by carefully taking the massless limit of the Proca field to eliminate nonphysical gauge modes.
GENERAL RELATIVITY AND GRAVITATION
(2023)
Correction
Computer Science, Hardware & Architecture
Gaurav Khanna, Sanjay K. Chaturvedi, Mohamed Othman
JOURNAL OF SUPERCOMPUTING
(2023)
Article
Astronomy & Astrophysics
Tessa Baker, Enrico Barausse, Anson Chen, Claudia de Rham, Mauro Pieroni, Gianmassim Tasinto
Summary: Effective field theories (EFT) of dark energy (DE) are limited by constraints on the propagation speed of gravitational waves (GW) but can still be valid at scales beyond the EFT description. Lower frequency observations by LISA would be harder to escape, while a joint observation by LISA and a terrestrial interferometer could constrain the speed of light and gravitons to within 10^-15. Multiband GW observations can therefore effectively constrain DE scenarios based on EFT.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Review
Physics, Particles & Fields
Pau Amaro-Seoane, Jeff Andrews, Manuel Arca Sedda, Abbas. Askar, Quentin Baghi, Razvan Balasov, Imre Bartos, Simone S. Bavera, Jillian Bellovary, Christopher P. L. Berry, Emanuele Berti, Stefano Bianchi, Laura Blecha, Stephane Blondin, Tamara Bogdanovic, Samuel Boissier, Matteo Bonetti, Silvia Bonoli, Elisa Bortolas, Katelyn Breivik, Pedro R. Capelo, Laurentiu Caramete, Federico Cattorini, Maria Charisi, Sylvain Chaty, Xian Chen, Martyna Chruslinska, Alvin J. K. Chua, Ross Church, Monica Colpi, Daniel D'Orazio, Camilla Danielski, Melvyn B. Davies, Pratika Dayal, Alessandra De Rosa, Andrea Derdzinski, Kyriakos Destounis, Massimo Dotti, Ioana Dutan, Irina Dvorkin, Gaia Fabj, Thierry Foglizzo, Saavik Ford, Jean-Baptiste Fouvry, Alessia Franchini, Tassos Fragos, Chris Fryer, Massimo Gaspari, Davide Gerosa, Luca Graziani, Paul Groot, Melanie Habouzit, Daryl Haggard, Zoltan Haiman, Wen-Biao Han, Alina Istrate, Peter H. Johansson, Fazeel Mahmood Khan, Tomas Kimpson, Kostas Kokkotas, Albert Kong, Valeriya Korol, Kyle Kremer, Thomas Kupfer, Astrid Lamberts, Shane Larson, Mike Lau, Dongliang Liu, Nicole Lloyd-Ronning, Giuseppe Lodato, Alessandro Lupi, Chung-Pei Ma, Tomas Maccarone, Ilya Mandel, Alberto Mangiagli, Michela Mapelli, Stephane Mathis, Lucio Mayer, Sean McGee, Berry McKernan, M. Coleman Miller, David F. Mota, Matthew Mumpower, Syeda S. Nasim, Gijs Nelemans, Scott Noble, Fabio Pacucci, Francesca Panessa, Vasileios Paschalidis, Hugo Pfister, Delphine Porquet, John Quenby, Angelo Ricarte, Friedrich K. Roepke, John Regan, Stephan Rosswog, Ashley Ruiter, Milton Ruiz, Jessie Runnoe, Raffaella Schneider, Jeremy Schnittman, Amy Secunda, Alberto Sesana, Naoki Seto, Lijing Shao, Stuart Shapiro, Carlos Sopuerta, Nicholas C. Stone, Arthur Suvorov, Nicola Tamanini, Tomas Tamfal, Thomas Tauris, Karel Temmink, John Tomsick, Silvia Toonen, Alejandro Torres-Orjuela, Martina Toscani, Antonios Tsokaros, Caner Unal, Veronica Vazquez-Aceves, Rosa Valiante, Maurice van Putten, Jan van Roestel, Christian Vignali, Marta Volonteri, Kinwah Wu, Ziri Younsi, Shenghua Yu, Silvia Zane, Lorenz Zwick, Fabio Antonini, Vishal Baibhav, Enrico Barausse, Alexander Bonilla Rivera, Marica Branchesi, Graziella Branduardi-Raymont, Kevin Burdge, Srija Chakraborty, Jorge Cuadra, Kristen Dage, Benjamin Davis, Selma E. de Mink, Roberto Decarli, Daniela Doneva, Stephanie Escoffier, Poshak Gandhi, Francesco Haardt, Carlos O. Lousto, Samaya Nissanke, Jason Nordhaus, Richard O'Shaughnessy, Simon Portegies Zwart, Adam Pound, Fabian Schussler, Olga Sergijenko, Alessandro Spallicci, Daniele Vernieri, Alejandro Vigna-Gomez
Summary: The Laser Interferometer Space Antenna (LISA) is an innovative experiment for gravitational wave astronomy, offering unique opportunities to address key astrophysical questions in a novel way. By synergizing with ground-based and space-born instruments, LISA enables multi-messenger observations, enhancing its discovery potential. This review highlights the extensive landscape of astrophysical theory, numerical simulations, and astronomical observations necessary for modeling and interpreting LISA's upcoming datastream. It also discusses open issues, gaps in understanding, and potential research avenues that LISA can contribute to in combination with electromagnetic domain studies.
LIVING REVIEWS IN RELATIVITY
(2023)
Article
Physics, Multidisciplinary
Mark Ho-Yeuk Cheung, Vishal Baibhav, Emanuele Berti, Vitor Cardoso, Gregorio Carullo, Roberto Cotesta, Walter Del Pozzo, Francisco Duque, Thomas Helfer, Estuti Shukla, Kaze W. K. Wong
Summary: We present evidence of nonlinear modes in the ringdown phase of gravitational waveforms generated by the merger of comparable-mass black holes. This evidence is based on numerical simulations of both quasicircular binary black hole coalescence and high-energy head-on collisions of black holes. The presence of nonlinear modes in the simulations highlights the importance of considering general-relativistic nonlinearities in the analysis of gravitational wave data.
PHYSICAL REVIEW LETTERS
(2023)
Article
Economics
Gaurav Khanna, Priya Mukherjee
Summary: We investigate the electoral effects of India's 2016 demonetization policy, which was supported by a majority of voters despite causing severe cash shortages and economic hardship. Our analysis shows that voters in areas with more severe demonetization had less favorable views of the policy, leading to a decrease in support for the ruling party.
JOURNAL OF PUBLIC ECONOMICS
(2023)
Review
Physics, Particles & Fields
Pierre Auclair, David Bacon, Tessa Baker, Tiago Barreiro, Nicola Bartolo, Enis Belgacem, Nicola Bellomo, Ido Ben-Dayan, Daniele Bertacca, Marc Besancon, Jose J. Blanco-Pillado, Diego Blas, Guillaume Boileau, Gianluca Calcagni, Robert Caldwell, Chiara Caprini, Carmelita Carbone, Chia-Feng Chang, Hsin-Yu Chen, Nelson Christensen, Sebastien Clesse, Denis Comelli, Giuseppe Congedo, Carlo Contaldi, Marco Crisostomi, Djuna Croon, Yanou Cui, Giulia Cusin, Daniel Cutting, Charles Dalang, Valerio De Luca, Walter Del Pozzo, Vincent Desjacques, Emanuela Dimastrogiovanni, Glauber C. Dorsch, Jose Maria Ezquiaga, Matteo Fasiello, Daniel G. Figueroa, Raphael Flauger, Gabriele Franciolini, Noemi Frusciante, Jacopo Fumagalli, Juan Garcia-Bellido, Oliver Gould, Daniel Holz, Laura Iacconi, Rajeev Kumar Jain, Alexander C. Jenkins, Ryusuke Jinno, Cristian Joana, Nikolaos Karnesis, Thomas Konstandin, Kazuya Koyama, Jonathan Kozaczuk, Sachiko Kuroyanagi, Danny Laghi, Marek Lewicki, Lucas Lombriser, Eric Madge, Michele Maggiore, Ameek Malhotra, Michele Mancarella, Vuk Mandic, Alberto Mangiagli, Sabino Matarrese, Anupam Mazumdar, Suvodip Mukherjee, Ilia Musco, Germano Nardini, Jose Miguel No, Theodoros Papanikolaou, Marco Peloso, Mauro Pieroni, Luigi Pilo, Alvise Raccanelli, Sebastien Renaux-Petel, Arianna I. Renzini, Angelo Ricciardone, Antonio Riotto, Joseph D. Romano, Rocco Rollo, Alberto Roper Pol, Ester Ruiz Morales, Mairi Sakellariadou, Ippocratis D. Saltas, Marco Scalisi, Kai Schmitz, Pedro Schwaller, Olga Sergijenko, Geraldine Servant, Peera Simakachorn, Lorenzo Sorbo, Lara Sousa, Lorenzo Speri, Daniele A. Steer, Nicola Tamanini, Gianmassimo Tasinato, Jesus Torrado, Caner Unal, Vincent Vennin, Daniele Vernieri, Filippo Vernizzi, Marta Volonteri, Jeremy M. Wachter, David Wands, Lukas T. Witkowski, Miguel Zumalacarregui, James Annis, Feanor Reuben Ares, Pedro P. Avelino, Anastasios Avgoustidis, Enrico Barausse, Alexander Bonilla, Camille Bonvin, Pasquale Bosso, Matteo Calabrese, Mesut Caliskan, Jose A. R. Cembranos, Mikael Chala, David Chernoff, Katy Clough, Alexander Criswell, Saurya Das, Antonio da Silva, Pratika Dayal, Valerie Domcke, Ruth Durrer, Richard Easther, Stephanie Escoffier, Sandrine Ferrans, Chris Fryer, Jonathan Gair, Chris Gordon, Martin Hendry, Mark Hindmarsh, Deanna C. Hooper, Eric Kajfasz, Joachim Kopp, Savvas M. Koushiappas, Utkarsh Kumar, Martin Kunz, Macarena Lagos, Marc Lilley, Joanes Lizarraga, Francisco S. N. Lobo, Azadeh Maleknejad, C. J. A. P. Martins, P. Daniel Meerburg, Renate Meyer, Jose Pedro Mimoso, Savvas Nesseris, Nelson Nunes, Vasilis Oikonomou, Giorgio Orlando, Ogan Ozsoy, Fabio Pacucci, Antonella Palmese, Antoine Petiteau, Lucas Pinol, Simon Portegies Zwart, Geraint Pratten, Tomislav Prokopec, John Quenby, Saeed Rastgoo, Diederik Roest, Kari Rummukainen, Carlo Schimd, Aurelia Secroun, Alberto Sesana, Carlos F. Sopuerta, Ismael Tereno, Andrew Tolley, Jon Urrestilla, Elias C. Vagenas, Jorinde van de Vis, Rien van de Weygaert, Barry Wardell, David J. Weir, Graham White, Bogumila Swiezewska, Valery I. Zhdanov
Summary: This publication provides an overview of the latest advancements in LISA cosmology, including theory and methods, and identifies new opportunities to probe the universe using gravitational-wave observations by LISA.
LIVING REVIEWS IN RELATIVITY
(2023)
Article
Physics, Multidisciplinary
Clemente Smarra, Boris Goncharov, Enrico Barausse, J. Antoniadis, S. Babak, A. -S. Bak Nielsen, C. G. Bassa, A. Berthereau, M. Bonetti, E. Bortolas, P. R. Brook, M. Burgay, R. N. Caballero, A. Chalumeau, D. J. Champion, S. Chanlaridis, S. Chen, I Cognard, G. Desvignes, M. Falxa, R. D. Fredman, A. Franchini, J. R. Gair, E. Graikou, J. -M. Griessmeier, L. Guillemot, Y. J. Guo, H. Hu, F. Iraci, D. Izquierdo-Villalba, J. Jang, J. Jawor, G. H. Janssen, A. Jessner, R. Karuppusamy, E. F. Keane, M. J. Keith, M. Kramer, M. A. Krishnakumar, K. Lackeos, K. J. Lee, K. Liu, Y. Liu, A. G. Lyne, J. W. Mckee, R. A. Main, M. B. Mickaliger, I. C. Nitu, A. Parthasarathy, B. B. P. Perera, D. Perrodin, A. Petiteau, N. K. Porayko, A. Possenti, H. Quelquejay Leclere, A. Samajdar, S. A. Sanidas, A. Sesana, G. Shaifullah, L. Speri, R. Spiewak, B. W. Stappers, S. C. Susarla, G. Theureau, C. Tiburzi, E. van der Wateren, A. Vecchio, V. Venkatraman Krishnan, J. Wang, L. Wang
Summary: Pulsar Timing Array experiments aim to detect possible ultralight dark matter particles through long-term timing of galactic millisecond radio pulsars. The latest data release suggests that these ultralight particles, which interact with ordinary matter solely through gravity, cannot account for 100% of the measured local dark matter density, but may have a local density of up to 0.3 GeV/cm(3).
PHYSICAL REVIEW LETTERS
(2023)
Article
Astronomy & Astrophysics
Justin C. Feng, Sumanta Chakraborty, Vitor Cardoso
Summary: We propose a shielding mechanism for a charged black hole in the presence of charged matter fields based on the Einstein-Maxwell field equations. By considering a charged generalization of the Einstein cluster, we demonstrate the existence of this shielding mechanism in different parameterizations. Additionally, we provide the most general electrovacuum solution in a charge-free spacetime region but with a static and spherically symmetric charge distribution elsewhere, as well as a convenient parameterization for the global solution of the Einstein-Maxwell's field equations in the presence of a charged black hole and charged fluid environment. Furthermore, we discuss the properties of the photon sphere, shadow radius, and eikonal quasinormal modes in the Einstein-Maxwell cluster.
Article
Astronomy & Astrophysics
Guillermo Lara, Miguel Bezares, Marco Crisostomi, Enrico Barausse
Summary: This study investigates neutron star solutions in scalar-tensor theories of gravity with first-order derivative selfinteractions in the action and in the matter coupling. The robustness of the kinetic screening mechanism against general conformal couplings to matter is assessed. It is found that kinetic screening always prevails over scalarization and that kinetic couplings with matter enhance the suppression of scalar gradients inside the star even more, without relying on the nonlinear regime. Fine tuning the kinetic coupling with the derivative self-interactions in the action allows one to partially cancel the latter, resulting in a weakening of kinetic screening inside the star. This effect represents a novel way to break screening mechanisms inside matter sources and provides new signatures that might be testable with astrophysical observations.
Article
Mathematics, Applied
Scott E. Field, Sigal Gottlieb, Zachary J. Grant, Leah F. Isherwood, Gaurav Khanna
Summary: We developed and utilized a novel mixed-precision weighted essentially non-oscillatory method for solving the Teukolsky equation in perturbations of Kerr black holes. Compared to higher-order finite-difference methods commonly used in discretization, we found that our WENO method outperforms due to its lack of dissipation requirements for stability. Our approach is well-suited for long-time evolution scenarios, such as studying price tails and gravitational wave emission from extreme mass ratio binaries. By performing the computationally expensive WENO weight calculations in reduced floating-point precision, we achieved a significant speedup factor of approximately 3.3. Additionally, we employed state-of-the-art Nvidia GPUs and cluster parallelism to further accelerate our WENO computations. Our optimized WENO solver generates accurate results quickly, which is of great significance in black hole and gravitational wave physics. We applied our solver to study the behavior of Aretakis charge, a conserved quantity that, if detected by a gravitational wave observatory like LIGO/Virgo, would provide evidence for the existence of extremal black holes.
COMMUNICATIONS ON APPLIED MATHEMATICS AND COMPUTATION
(2023)