Article
Astronomy & Astrophysics
Raphal van Laak, Sam Young
Summary: Primordial black holes are black holes that may have formed in high density regions in the early universe. The fluctuations in their formation rate can be used to constrain the amplitude of non-Gaussianity, especially if primordial black holes make up a significant fraction of dark matter. By extending the calculation to include peaks theory and considering the non-linearities between compaction C and curvature perturbation C, we find that the constraints on quadratic models of non-Gaussianity are largely unchanged, while the constraints on cubic models significantly worsen. If all of the dark matter is composed of primordial black holes, the parameters of non-Gaussianity are -2.9 & BULL; 10-4 < f < 3.8 & BULL; 10-4 and -1.5 & BULL; 10-3 < g < 1.9 & BULL; 10-3 for quadratic and cubic models respectively.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Sam Young
Summary: In this study, we reassess the impact of local-type non-Gaussianity on the abundance of primordial black holes (PBHs) and find that the effect is much less significant than previously believed. The non-Gaussianity parameters need to be significantly larger to have a similar effect as before, which weakens the constraints on PBH abundance and the primordial power spectrum dependence on non-Gaussianity parameters. Furthermore, we question the existing calculations of PBH abundance due to the correlation between curvature perturbation and compaction.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Astronomy & Astrophysics
Giacomo Ferrante, Gabriele Franciolini, Antonio Junior Iovino, Alfredo Urbano
Summary: We revise the production of primordial black holes (PBHs) in the axion-curvaton model by considering recent developments in the computation of their abundance accounting for nongaussianities (NGs) in the curvature perturbation. We find that the intrinsic NGs generated in such scenarios have a significant impact on the phenomenology associated with PBHs, particularly on the relationship between their abundance and the second order gravitational wave signal. Additionally, we demonstrate that this model can potentially explain the entire dark matter content in the asteroid mass range and the signal reported in the nano-Hz frequency range by the NANOGrav and IPTA collaborations. Along the way, we provide a new explicit computation of the power spectrum of curvature perturbations that goes beyond the sudden decay approximation.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Christopher S. Gallagher, Timothy Clifton, Chris Clarkson
Summary: Two-parameter perturbation theory is a framework designed to study the relativistic gravitational effects of small-scale nonlinear structures on the large-scale properties of the Universe. The approach in this paper uses Newtonian perturbation theory to model the gravitational fields of quasi-nonlinear structures and then applies them as source terms for large-scale cosmological perturbations. This work represents a first step towards deploying a formalism that can simultaneously model the weak gravitational fields of both linear and nonlinear structures in a realistic model of the Universe.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Teppei Minoda, Kiyotomo Ichiki, Hiroyuki Tashiro
Summary: This paper investigates how primordial magnetic fields (PMFs) in the early universe affect cosmic microwave background (CMB) anisotropies, and constrains the PMFs using data from Planck and South Pole Telescope (SPT). The results indicate that the SPT data support a PMF model with small scale dependence.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Julian Adamek, Juan Calles, Thomas Montandon, Jorge Norena, Clement Stahl
Summary: Relativistic corrections to the evolution of structure can be tested using the numerical framework presented in this study. The framework generates RELativistic second-order Initial Conditions (RELIC) based on a generic second-order kernel for density perturbations. The results show that the generated initial conditions reproduce bispectra well, demonstrating the effectiveness of the framework. Additionally, a generic algorithm is provided to set precise initial conditions for cosmological simulations of large-scale structure.
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2022)
Article
Multidisciplinary Sciences
Sehoon Park, Soojin Lee, Yaerim Kim, Yeonhee Lee, Min Woo Kang, Kwangsoo Kim, Yong Chul Kim, Seung Seok Han, Hajeong Lee, Jung Pyo Lee, Kwon Wook Joo, Chun Soo Lim, Yon Su Kim, Dong Ki Kim
Summary: This study found that taller adult height is causally linked to worse kidney function in middle-aged to elderly individuals, independent of the effect of body mass index.
Article
Green & Sustainable Science & Technology
P. Mucchielli, B. Bhowmik, B. Ghosh, V Pakrashi
Summary: This study investigates the utility of wind power and wind speed as potential parameters for real-time downtime detection. A real-time downtime detection framework is proposed that maps system outputs to turbine events faults, scheduled, and unplanned maintenance through online condition indicators.
Article
Biochemistry & Molecular Biology
Thibault Latrille, Nicolas Lartillot
Summary: Phylogenetic codon models are often used to study selective pressures in coding sequences, but the parametric design, particularly in relation to nucleotide frequencies and substitution rates, is still debated. The discrepancy comes from the fact that the models do not accurately capture the differences in nucleotide composition among the three coding positions, leading to inaccurate estimates of selection strength. An improved modeling approach that considers fixation rate as a tensor is proposed to address this issue by more accurately capturing the interaction between mutation and selection.
MOLECULAR BIOLOGY AND EVOLUTION
(2022)
Article
Water Resources
Carlos A. S. Ferreira, Hamidreza M. Nick
Summary: This study proposes an integrated framework for obtaining fracture networks with real aperture distributions based on X-ray computed tomography (CT) images of core plugs from naturally fractured rock formations. The framework utilizes segmentation, skeletonization, and geometry generation algorithms available in open-source libraries and licensed software. In addition, fluid flow simulations are conducted to investigate the contributions of fractures and porous matrix to the equivalent permeability tensor.
ADVANCES IN WATER RESOURCES
(2023)
Article
Surgery
Dennis M. Vaysburg, Alexander R. Cortez, Dennis J. Hanseman, Aaron M. Delman, Christopher Morris, Al-Faraaz Kassam, David Kutz, Jaime Lewis, Robert M. Van Haren, R. Cutler Quillin
Summary: This study evaluated the trends and competitiveness of general surgery, integrated programs, and surgical subspecialties matches over the past decade. The findings indicate that integrated programs and surgical subspecialties have attracted more competitive applicants, while general surgery is relatively less competitive.
Article
Astronomy & Astrophysics
Wei-Ting Liao, Matthew Turk, Hsi-Yu Schive
Summary: This study investigates the possibility of generating a coherent magnetic field through large-scale dynamo processes during the accretion phase of Population III stars, and determines the corresponding saturation level. Helical turbulence plays a crucial role in facilitating the growth of large-scale dynamo modes, with the saturation level being determined by the net helicity remaining in the dynamo active regions.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Kwan Chuen Chan, Nico Hamaus
Summary: The study examines the distribution of underdense regions in the large-scale structure of the Universe using volume statistics and tessellation methods. Voronoi and Delaunay tessellation are applied to analyze the clustering properties of density and volume statistics. Both methods show a similar level of shot-noise contamination, making them effective in field estimation.
Article
Mathematics
Mingle Zhou, Ming Cai, Gang Li, Min Li
Summary: This paper proposes an end-to-end encoder-decoder framework with an attention mechanism to convert formulas in pictures into LaTeX sequences. Positional embedding is introduced to accurately capture the position and spatial characteristics of formula characters. The experiment shows that BLEU reaches 92.11, MED is 0.90, and Exact Match(EM) is 0.62 on the im2latex-100k dataset.
Article
Mathematics, Applied
Junhyun Cho, Yejin Kim, Sungchul Lee
Summary: In this paper, we propose an unconditionally stable numerical algorithm for accurate option pricing and hedge parameters based on the Feynman-Kac formula of the Black-Scholes equation. The algorithm discretizes the asset and time using uniform grid points and utilizes piecewise quadratic polynomial approximation and analytic integration to achieve higher accuracy and convergence. Additionally, the algorithm demonstrates stability and low time complexity through backward propagation of estimation errors following the convection and diffusion characteristics of the Black-Scholes equation.
APPLIED MATHEMATICS AND COMPUTATION
(2022)
Article
Astronomy & Astrophysics
Kenji Kadota, Jinn-Ouk Gong, Kiyotomo Ichiki, Takahiko Matsubara
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2015)
Article
Astronomy & Astrophysics
Takahiko Matsubara
Article
Astronomy & Astrophysics
D. Munshi, B. Hu, T. Matsubara, P. Coles, A. Heavens
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2016)
Article
Astronomy & Astrophysics
Shintaro Yoshiura, Hayato Shimabukuro, Keitaro Takahashi, Takahiko Matsubara
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2017)
Article
Astronomy & Astrophysics
Kazuhiro Kogai, Takahiko Matsubara, Atsushi J. Nishizawa, Yuko Urakawa
JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS
(2018)
Article
Astronomy & Astrophysics
Takahiko Matsubara
Article
Astronomy & Astrophysics
Shuichiro Yokoyama, Takahiko Matsubara, Atsushi Taruya
Article
Instruments & Instrumentation
A. Blondel, M. Bogomilov, S. Bordoni, F. Cadoux, D. Douqa, K. Dugas, T. Ekelof, Y. Favre, S. Fedotov, K. Fransson, R. Fujita, E. Gramstad, A. K. Ichikawa, S. Ilieva, K. Iwamoto, C. Jesus-Valls, C. K. Jung, S. P. Kasetti, M. Khabibullin, A. Khotjantsev, A. Korzenev, A. Kostin, Y. Kudenko, T. Kutter, T. Lux, L. Maret, T. Matsubara, A. Mefodiev, A. Minamino, O. Mineev, G. Mitev, M. Nessi, L. Nicola, E. Noah, S. Parsa, G. Petkov, F. Sanchez, D. Sgalaberna, W. Shorrock, K. Skwarczynski, S. Suvorov, A. Teklu, R. Tsenov, Y. Uchida, G. Vankova-Kirilova, N. Yershov, M. Yokoyama, J. Zalipska, Y. Zou, W. Zurek
JOURNAL OF INSTRUMENTATION
(2020)
Article
Astronomy & Astrophysics
Takahiko Matsubara, Sandrine Codis
Article
Astronomy & Astrophysics
Takahiko Matsubara
Article
Astronomy & Astrophysics
Hiroyuki Kitamoto, Yoshihisa Kitazawa, Takahiko Matsubara
Article
Astronomy & Astrophysics
Takahiko Matsubara, Takahiro Terada, Kazunori Kohri, Shuichiro Yokoyama
Article
Astronomy & Astrophysics
Takahiko Matsubara
Article
Astronomy & Astrophysics
Takahiko Matsubara, Vincent Desjacques
Article
Astronomy & Astrophysics
Ichihiko Hashimoto, Atsushi Taruya, Takahiko Matsubara, Toshiya Namikawa, Shuichiro Yokoyama