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Tori of Active Galactic Nuclei are made up of a mixture of hot and cold gas, as well as dust. In order to protect the dust grains from destruction by the hot gas as well as by the energetic radiation of the accretion disk, the dust is often…

Astrophysics · Physics 2009-11-13 M. Schartmann , K. Meisenheimer , M. Camenzind , S. Wolf , K. R. W. Tristram , Th. Henning

In this paper we implement a numerical algorithm to compute codimension-one tori in three-dimensional, volume-preserving maps. A torus is defined by its conjugacy to rigid rotation, which is in turn given by its Fourier series. The…

Chaotic Dynamics · Physics 2013-10-01 Adam M. Fox , James D. Meiss

Many approaches to galaxy dynamics assume that the gravitational potential is simple and the distribution function is time-invariant. Under these assumptions there are traditional tools for inferring potential parameters given observations…

Dissipative mechanical systems on the torus with a friction that is proportional to the velocity are modeled by conformally symplectic maps on the annulus, which are maps that transport the symplectic form into a multiple of itself (with a…

Dynamical Systems · Mathematics 2021-02-03 Renato Calleja , Marta Canadell , Alex Haro

Orbital Torus Imaging (OTI) is a dynamical inference method for determining the Milky Way's gravitational potential using stellar survey data. OTI uses gradients in stellar astrophysical quantities, such as element abundances, as functions…

Astrophysics of Galaxies · Physics 2025-05-12 Micah Oeur , Sarah R. Loebman , Adrian M. Price-Whelan , Arpit Arora , Lina Necib , Danny Horta

We describe improved modelling of the emission by dust in a toroidal--like structure heated by a central illuminating source within Active Galactic Nuclei (AGN). We chose a simple but realistic torus geometry, a flared disc, and a dust…

Astrophysics · Physics 2009-11-13 J. Fritz , A. Franceschini , E. Hatziminaoglou

We consider autonomous Hamiltonian systems and present an algorithm to compute at the same time partially hyperbolic invariant tori (whiskered tori), as well as high-order expansions of their stable and unstable manifolds. Such whiskered…

Dynamical Systems · Mathematics 2025-07-09 Álvaro Fernández-Mora , Àlex Haro , Rafael de la Llave , Josep-Maria Mondelo

We study the existence of whiskered tori in a family $f_\mu$ of conformally symplectic maps depending on parameters $\mu$. Whiskered tori are tori on which the motion is a rotation, but they have as many expanding/contracting directions as…

Dynamical Systems · Mathematics 2020-01-08 Renato C. Calleja , Alessandra Celletti , Rafael de la Llave

After carefully considering the scalability problem in Tor and exhaustively evaluating related works on AS-level adversaries, the author proposes ASmoniTor, which is an autonomous system monitor for mitigating correlation attacks in the Tor…

Cryptography and Security · Computer Science 2016-10-10 Nguyen Phong Hoang

Unified schemes of active galactic nuclei (AGN) require an obscuring dusty torus around the central engine. Torus sizes of hundreds of parsecs were deduced from early theoretical modeling efforts, but high-resolution IR observations now…

Astrophysics · Physics 2007-05-23 Moshe Elitzur

We compute the integral cohomology of certain semi-direct products arising from a linear G-action on the n-torus, where G is a finite group. The main application is the complete calculation of torsion gerbes for certain six dimensional…

Algebraic Topology · Mathematics 2007-05-23 Alejandro Adem , Jianzhong Pan

We propose a method for computing generating functions of genus-zero invariants of a gauged linear sigma model $(V, G, \theta, w)$. We show that certain derivatives of $I$-functions of quasimap invariants of $[V //_\theta G]$ produce…

Algebraic Geometry · Mathematics 2026-01-01 Mark Shoemaker

A covariant functor from the category of mapping tori to a category of AF-algebras is constructed; the functor takes continuous maps between such manifolds to stable homomorphisms between the corresponding AF-algebras. We use this functor…

Operator Algebras · Mathematics 2016-01-14 Igor Nikolaev

We present the first results of the Galaxy Activity, Torus and Outflow Survey (GATOS), a project aimed at understanding the properties of the dusty molecular tori and their connection to the host galaxy in nearby Seyfert galaxies. Our…

There has been a recent surge in learning generative models for graphs. While impressive progress has been made on static graphs, work on generative modeling of temporal graphs is at a nascent stage with significant scope for improvement.…

Machine Learning · Computer Science 2022-08-26 Shubham Gupta , Sahil Manchanda , Srikanta Bedathur , Sayan Ranu

Using the radiative transfer code Torus, we produce spectral-line cubes of the predicted HI profile from global SPH simulations of spiral galaxies. Torus grids the SPH galaxy using Adaptive Mesh Refinement, then applies a ray-tracing method…

Astrophysics of Galaxies · Physics 2009-09-02 Kevin A. Douglas , David Acreman , Clare Dobbs , Chris Brunt

We introduce innovative algorithms for computing exact or approximate (minimum-norm) solutions to $Ax=b$ or the {\it normal equation} $A^TAx=A^Tb$, where $A$ is an $m \times n$ real matrix of arbitrary rank. We present more efficient…

Numerical Analysis · Mathematics 2023-11-30 Bahman Kalantari

Approximate computing is an emerging paradigm for developing highly energy-efficient computing systems such as various accelerators. In the literature, many libraries of elementary approximate circuits have already been proposed to simplify…

Distributed, Parallel, and Cluster Computing · Computer Science 2019-06-13 Vojtech Mrazek , Muhammad Abdullah Hanif , Zdenek Vasicek , Lukas Sekanina , Muhammad Shafique

Toric codes are obtained by evaluating rational functions of a nonsingular toric variety at the algebraic torus. One can extend toric codes to the so called generalized toric codes. This extension consists on evaluating elements of an…

Information Theory · Computer Science 2010-02-25 Diego Ruano

Solving the shallow water equations efficiently is critical to the study of natural hazards induced by tsunami and storm surge, since it provides more response time in an early warning system and allows more runs to be done for…

Computational Physics · Physics 2019-01-23 Xinsheng Qin , Randall LeVeque , Michael Motley