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The School on String Theory, Quantum Field Theory and Geometry of Spacetime
Quantum Field Theory and Geometry Geometry of Spacetime
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2016/7/19
The School on String Theory, Quantum Field Theory and Geometry of Spacetime will take place at Tsinghua University, Beijing, China, from July 24 to July 28, 2016, the week before Strings 2016. Topics ...
Emission geometry, radiation pattern, and magnetic topology of the magnetar XTE J1810-197 in its quiescent state
pulsars: general – stars: neutron – X-rays: individual: XTE J1810− 197
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2011/10/17
The return to the quiescent state of the Anomalous X-ray pulsar XTE J1810-197 following its 2003 outburst represents a unique opportunity to probe the surface emission properties of a magnetar. The qu...
Acceleration of particles by rotating black holes: near-horizon geometry and kinematics
Acceleration particles rotating black holes: near-horizon geometry kinematics
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2011/10/14
Nowadays, the effect of infinite energy in the centre of mass frame due to near-horizon collisions attracts much attention.We show generality of the effect combining two seemingly completely different...
A Suzaku Observation of MCG-2-58-22: Constraining the Geometry of the Circumnuclear Material
Observation MCG-2-58-22 Constraining Geometry clear Material
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2011/9/26
We have analyzed a Suzaku long-look of the active galactic nucleus MCG-2-58-22, a type 1.5 Seyfert with very little X-ray absorption in the line of sight and prominent features arising from reflection...
A Suzaku Observation of MCG-2-58-22: Constraining the Geometry of the Circumnuclear Material
Galaxies: active – X-rays galaxies – Galaxies Individual
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2011/8/24
We have analyzed a Suzaku long-look of the active galactic nucleus MCG-2-58-22, a type 1.5 Seyfert with very little X-ray absorption in the line of sight and prominent features arising from reflection...
The role of flow geometry in influencing the stability criteria for low angular momentum axisymmetric black hole accretion
the stability criteria low angular momentum axisymmetric black hole accretion
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2011/1/11
Using mathematical formalism borrowed from dynamical systems theory, a complete analytical investigation of the critical behaviour of the stationary flow configuration for the low angular momentum axi...
The geometry of the filamentary environment of galaxy clusters
geometry filamentary environment galaxy clusters
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2010/11/10
We construct a filament catalogue using an extension of the halo based filament finder
of Zhang et al. (2009), in a 250 Mpc/h side N-body simulation, and study the prop-
erties of filaments ending u...
Monte Carlo simulations of the Nickel K$\alpha$ fluorescent emission line in a toroidal geometry
galaxies active - line formation - radiation mechanism general - scattering - X-rays general
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2010/11/12
We present new results from Monte Carlo calculations of the flux and equivalent width(EW) of the Ni K fluorescent emission line in the toroidal X-ray reprocessor model of Murphy & Yaqoob (2009, MNRAS...
Simulating Heliospheric and Solar Particle Diffusion using the Parker Spiral Geometry
Simulating Heliospheric Solar Particle Diffusion Parker Spiral Geometry
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2010/11/16
Cosmic Ray transport in curved background magnetic fields is investigated using numerical Monte-Carlo simulation techniques. Special emphasis is laid on the So-lar system, where the curvature of the m...
A New Method for Determining Geometry of Planetary Images
Instrumentation and Methods for Astrophysics (astro-ph.IM)
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2010/12/27
This paper presents a novel semi-automatic image processing technique to estimate accurately, and objectively, the disc parameters of a planetary body on an astronomical image.
Cosmology in One Dimension:Fractal Geometry, Power Spectra and Correlation
One Dimension Fractal Geometry Power Spectra
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2010/4/6
Concentrations of matter, such as galaxies and galactic clusters, originated as very small density fluctuations in the early universe. The existence of galaxy clusters and super-clusters suggests that...
Energy in an Expanding Universe in the Teleparallel Geometry
Gravitation teleparallelism gravitational energy- momentum tensor
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2010/6/30
The main purpose of this paper is to explicitly verify the consistency of the energy-momentum and angular momentum tensor of the gravitational field established in the Hamiltonian structure of the Tel...
The matter Lagrangian and the energy-momentum tensor in modified gravity with non-minimal coupling between matter and geometry
energy-momentum tensor modified gravity non-minimal coupling
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2010/3/18
We show that in modified $f(R)$ type gravity models with non-minimal coupling between matter and geometry, both the matter Lagrangian, and the energy-momentum tensor, are completely and uniquely deter...
Geometry and observables in (2+1)-gravity
vacuum spacetimes (2+1)-gravity geometrical properties
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2010/3/18
We review the geometrical properties of vacuum spacetimes in (2+1)-gravity with vanishing cosmological constant. We explain how these spacetimes are characterised as quotients of their universal cover...
Geometry of the quantum universe
causal dynamical triangulation
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2010/3/19
A universe much like the (Euclidean) de Sitter space-time appears as background geometry in the causal dynamical triangulation (CDT) regularization of quantum gravity. We study the geometry of such un...