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The precise radial velocity technique is a cornerstone of exoplanetary astronomy. Astronomers measure Doppler shifts in the star's spectral features, which track the line-of/sight gravitational accelerations of a star caused by the planets…

Earth and Planetary Astrophysics · Physics 2019-02-06 Jason T. Wright

A procedure is described of construction of velocity fields and velocity dispersion of the stellar component in the central regions of galaxies on the basis of data obtained with the integral field spectrograph MPFS. Cross-correlation and…

Astrophysics · Physics 2007-05-23 A. V. Moiseev

In this preliminary study, we provide two methods for estimating the gradients of functions of real value. Both methods are built on derivative estimations that are calculated using the standard method or the Squire-Trapp method for any…

Numerical Analysis · Mathematics 2023-12-04 Ergun Akleman , Alan Freed

Measuring stellar rotational velocities is a powerful way to probe the many astrophysical phenomena that drive, or are driven by, the evolution of stellar angular momentum. In this paper, we present a novel data-driven approach to measuring…

Solar and Stellar Astrophysics · Physics 2019-04-17 Steven Gilhool , Cullen Blake

We develop and analyze efficient "coordinate-wise" methods for finding the leading eigenvector, where each step involves only a vector-vector product. We establish global convergence with overall runtime guarantees that are at least as good…

Numerical Analysis · Computer Science 2017-02-28 Jialei Wang , Weiran Wang , Dan Garber , Nathan Srebro

We develop a model independent, robust method for determining galaxy rotation velocities across a 2D array of spaxels from an integral field spectrograph. Simulations demonstrate the method is accurate down to lower spectral signal-to-noise…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-02 Mikhail Denissenya , Eric V. Linder , Sangwoo Park , Arman Shafieloo , Satadru Bag

Urban traffic speed prediction aims to estimate the future traffic speed for improving the urban transportation services. Enormous efforts have been made on exploiting spatial correlations and temporal dependencies of traffic speed evolving…

Machine Learning · Computer Science 2022-12-27 Dongkun Wang , Wei Fan , Pengyang Wang , Pengfei Wang , Dongjie Wang , Denghui Zhang , Yanjie Fu

The ordinal patterns of a fixed number of consecutive values in a time series is the spatial ordering of these values. Counting how often a specific ordinal pattern occurs in a time series provides important insights into the properties of…

Statistics Theory · Mathematics 2025-02-06 Annika Betken , Giorgio Micali , Johannes Schmidt-Hieber

Real-time detection of objects in the 3D scene is one of the tasks an autonomous agent needs to perform for understanding its surroundings. While recent Deep Learning-based solutions achieve satisfactory performance, their high…

Computer Vision and Pattern Recognition · Computer Science 2021-05-24 Illia Oleksiienko , Alexandros Iosifidis

As a planet transits the face of a star, it accelerates along the line-of-sight. The changing delay in the propagation of photons produces an apparent deceleration of the planet across the sky throughout the transit. This persistent…

Astrophysics · Physics 2009-11-10 Abraham Loeb

In this paper, we generalize the theory of the invariant subspace method to (m + 1)-dimensional non-linear time-fractional partial differential equations for the first time. More specifically, the applicability and efficacy of the method…

Exactly Solvable and Integrable Systems · Physics 2023-04-07 P. Prakash , K. S. Priyendhu , M. Lakshmanan

This paper discusses a novel approach for detecting moving massive objects based on the time variation that these objects produce in the local gravitational field measured by several detectors. Such an approach may provide a viable method…

Instrumentation and Detectors · Physics 2012-08-14 Emmanuel David Tannenbaum

Based on SGD, previous works have proposed many algorithms that have improved convergence speed and generalization in stochastic optimization, such as SGDm, AdaGrad, Adam, etc. However, their convergence analysis under non-convex conditions…

Machine Learning · Computer Science 2024-02-05 Yichuan Deng , Zhao Song , Chiwun Yang

Density waves in galaxy disks have been proposed over the years, in a variety of specific models, to explain spiral arm structure and its relation to the mass distribution, notably in barred galaxies. An important parameter in dynamical…

Astrophysics of Galaxies · Physics 2018-03-14 John E. Beckman , Joan Font , Alejandro Borlaff , Begoña García-Lorenzo

Future urban transportation concepts include a mixture of ground and air vehicles with varying degrees of autonomy in a congested environment. In such dynamic environments, occupancy maps alone are not sufficient for safe path planning.…

Robotics · Computer Science 2021-07-26 Ransalu Senanayake , Kyle Beltran Hatch , Jason Zheng , Mykel J. Kochenderfer

Modern convolutional neural networks apply the same operations on every pixel in an image. However, not all image regions are equally important. To address this inefficiency, we propose a method to dynamically apply convolutions conditioned…

Computer Vision and Pattern Recognition · Computer Science 2022-08-08 Thomas Verelst , Tinne Tuytelaars

This paper reports on a theoretical analysis of the rich variety of spatio-temporal patterns observed recently in inclined layer convection at medium Prandtl number when varying the inclination angle $\gamma$ and the Rayleigh number $R$.…

We consider the slowly rotating relativistic stars with a uniform angular velocity in the scalar-tensor gravity, and examine the rotational effect around such compact objects. For this purpose, we derive a 2nd order differential equation…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Hajime Sotani

In this paper, we introduce a novel numerical method for reconstructing the trajectory within three-dimensional space, where both the emission moment and spatial location of the point source are unknown. Our approach relies solely on…

Numerical Analysis · Mathematics 2025-07-29 Guanqiu Ma , Haonan Zhang , Hongxia Guo

We present a new approach for the identification of ultra-high energy cosmic rays from sources using dynamic graph convolutional neural networks. These networks are designed to handle sparsely arranged objects and to exploit their short-…

High Energy Astrophysical Phenomena · Physics 2020-12-09 Teresa Bister , Martin Erdmann , Jonas Glombitza , Niklas Langner , Josina Schulte , Marcus Wirtz
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