English
Related papers

Related papers: Time-Symmetrized Kustaanheimo-Stiefel Regularizati…

200 papers

Computational efficiency demands discretised, hierarchically organised, and individually adaptive time-step sizes (known as the block-step scheme) for the time integration of N-body models. However, most existing N-body codes adapt…

Instrumentation and Methods for Astrophysics · Physics 2017-09-20 Walter Dehnen

We present a simple algorithm to switch between $N$-body time integrators in a reversible way. We apply it to planetary systems undergoing arbitrarily close encounters and highly eccentric orbits, but the potential applications are broader.…

Earth and Planetary Astrophysics · Physics 2023-03-08 David M. Hernandez , Walter Dehnen

Kullback-Leibler divergence (KL) regularization is widely used in reinforcement learning, but it becomes infinite under support mismatch and can degenerate in low-noise limits. Utilizing a unified information-geometric framework, we…

Optimization and Control · Mathematics 2026-02-03 Viktor Stein , Adwait Datar , Nihat Ay

Long-range entangled states are vital for quantum information processing and quantum metrology. Preparing such states by combining measurements with unitary gates opened new possibilities for efficient protocols with finite-depth quantum…

Quantum Physics · Physics 2024-08-07 Iosifina Angelidi , Marcin Szyniszewski , Arijeet Pal

We present a new time-stepping criterion for N-body simulations that is based on the true dynamical time of a particle. This allows us to follow the orbits of particles correctly in all environments since it has better adaptivity than…

Astrophysics · Physics 2009-10-12 Marcel Zemp , Joachim Stadel , Ben Moore , C. Marcella Carollo

Efficient and accurate numerical algorithms are developed to solve a generalized Kirchhoff-Love plate model subject to three common physical boundary conditions: (i) clamped; (ii) simply supported; and (iii) free. We solve the model…

Numerical Analysis · Mathematics 2020-08-05 Duong T. A. Nguyen , Longfei Li , Hangjie Ji

Consider the scattering of a time-harmonic plane wave by a rigid obstacle embedded in a homogeneous and isotropic elastic medium in two dimensions. In this paper, a novel boundary integral formulation is proposed and its highly accurate…

Numerical Analysis · Mathematics 2020-07-20 Heping Dong , Jun Lai , Peijun Li

The need for the extra dimension in Kustaanheimo-Stiefel (KS) regularization is explained by the topology of the Hopf fibration, which defines the geometry and structure of KS space. A trajectory in Cartesian space is represented by a…

Mathematical Physics · Physics 2016-04-25 Javier Roa , Hodei Urrutxua , Jesús Peláez

A space-time collocation method (STCM) using asymptotically-constant basis functions is proposed and applied to the quantum Hamiltonian constraint for a loop-quantized treatment of the Schwarzschild interior. Canonically, these descriptions…

Computational Physics · Physics 2020-12-02 Alec Yonika , Alfa Heryudono , Gaurav Khanna

$N$-body integrations are used to model a wide range of astrophysical dynamics, but they suffer from errors which make their orbits diverge exponentially in time from the correct orbits. Over long time-scales, their reliability needs to be…

Earth and Planetary Astrophysics · Physics 2020-02-26 David M. Hernandez , Sam Hadden , Junichiro Makino

This paper deals with an implicit Newton-like inertial dynamical system governed by a maximally comonotone inclusion problem in a Hilbert space. Under suitable conditions, we establish not only pointwise estimates and integral estimates for…

Optimization and Control · Mathematics 2024-05-13 Z. Z. Tan , R. Hu , Y. P. Fang

The time dependent complex Schr\"odinger equation with cubic nonlinearity is solved by constructing differential quadrature algorithm based on sinc functions. Reduction to a coupled system of real equations enables to approach the space…

Numerical Analysis · Mathematics 2018-04-11 Alper Korkmaz

Numerical simulations of merging compact objects and their remnants form the theoretical foundation for gravitational wave and multi-messenger astronomy. While Cartesian-coordinate-based adaptive mesh refinement is commonly used for…

The complexity of the error correction circuitry forces us to design quantum error correction codes capable of correcting a single error per error correction cycle. Yet, time-correlated error are common for physical implementations of…

Quantum Physics · Physics 2007-05-23 Feng Lu , Dan C. Marinescu

The regularization of a new problem, namely the three-body problem, using 'similar' coordinate system is proposed. For this purpose we use the relation of 'similarity', which has been introduced as an equivalence relation in a previous…

Earth and Planetary Astrophysics · Physics 2011-10-31 Rodica Roman , Iharka Szucs-Csillik

We introduce a class of fourth order symplectic algorithms that are ideal for doing long time integration of gravitational few-body problems. These algorithms have only positive time steps, but require computing the force gradient in…

Astrophysics · Physics 2007-05-23 Siu A. Chin , C. R. Chen

We implement an algorithm which is aimed to reduce the number of basis states spanning the Hilbert space of quantum many-body systems. We test the efficiency of the procedure by working out and analyzing the spectral properties of strongly…

Quantum Physics · Physics 2007-05-23 Tarek Khalil , Jean Richert

We present a new symplectic integrator designed for collisional gravitational $N$-body problems which makes use of Kepler solvers. The integrator is also reversible and conserves 9 integrals of motion of the $N$-body problem to machine…

Instrumentation and Methods for Astrophysics · Physics 2017-03-03 David M. Hernandez , Edmund Bertschinger

This work presents an elegant formalism to model the evolution of the full two rigid body problem. The equations of motion, given in a Cartesian coordinate system, are expressed in terms of spherical harmonics and Wigner D-matrices. The…

Earth and Planetary Astrophysics · Physics 2017-02-08 Gwenaël Boué

We present a new time integrator for articulated body dynamics. We formulate the governing equations of the dynamics using only the position variables and recast the position-based articulated dynamics as an optimization problem. Our…

Robotics · Computer Science 2018-07-24 Zherong Pan , Dinesh Manocha