314 citations · 1.9k across the 49 of their papers we have counts for
23 papers · 1 filter
Geometrodynamical Distances to the Galaxy's Hydrogen Streams
Shoko Jin, Donald Lynden-Bell
We present a geometrodynamical method for determining distances to orbital streams of HI gas in the Galaxy. The method makes use of our offset from the Galactic centre and assumes…
Analytic Central Orbits and their Transformation Group
Donald Lynden-Bell, Shoko Jin
A useful crude approximation for Abelian functions is developed and applied to orbits. The bound orbits in the power-law potentials A*r^{-alpha} take the simple form (l/r)^k = 1 +…
Electromagnetic Fields in Jets
B. D. Sherwin, D. Lynden-Bell
The magnetic fields and energy flows in an astronomical jet described by our earlier model are calculated in detail. Though the field distribution varies with the external pressure…
Lattice Melting and Rotation in Perpetually Pulsating Equilibria
C. Pichon, D. Lynden-Bell, J. Pichon +1
Systems whose potential energies consists of pieces that scale as r^-2 together with pieces that scale as r^2, show no violent relaxation to Virial equilibrium but may pulsate at c…
An Orphan in the "Field of Streams"
V. Belokurov, N. W. Evans, M. J. Irwin +19
We use Sloan Digital Sky Survey Data Release 5 photometry and spectroscopy to study a tidal stream that extends over 50 degrees in the North Galactic Cap. From the analysis of the…
Hamilton's Eccentricity Vector Generalised to Newton Wonders
D. Lynden-Bell
The vectorial velocity is given as a function of the position of a particle in orbit when a Newtonian central force is supplemented by an inverse cubic force as in Newton's theorem…
Magnetic Jets from Swirling Disks
D. Lynden-Bell
A broad swathe of astrophysical phenomena, ranging from tubular planetary nebulae through Herbig-Haro objects, radio-galaxy and quasar emissions to gamma-ray bursts and perhaps hig…
Inconsistency in theories of violent-relaxation
I. Arad, D. Lynden-Bell
We examine an inconsistency in theories of violent-relaxation by Lynden-Bell and Nakamura. The inconsistency arises from the non-transitive nature of these theories: a system that…
A simple derivation and interpretation of the third integral in Stellar Dynamics
Donald Lynden-Bell
Starting from the problem of two fixed centres we find a simple derivation of its third integral in terms of the scalar product of the angular momenta about the two fixed centres.…
On Why Disks Generate Magnetic Towers and Collimate Jets
D Lynden-Bell
We show that accretion disks with magnetic fields in them ought to make jets provided that their electrical conductivity prevents slippage and there is an ambient pressure in their…
A Magic Electromagnetic Field
Donald Lynden-Bell
An electromagnetic field of simple algebraic structure is simply derived. It turns out to be the G=0 limit of the charged rotating Kerr-Newman metrics. These all have gyromagnetic…
Why Do Disks Form Jets?
D Lynden-Bell
It is argued that jet modelers have given insufficient study to the natural magneto-static configurations of field wound up in the presence of a confining general pressure. Such fi…
One Mass-Radius relation for Planets, White Dwarfs and Neutron Stars
D. Lynden-Bell, J. P. O'Dwyer
We produce the simple formula for the radius R of a cold body of mass M, (4 pi rho/3)^{1/3} R = I.M^{1/3} / [1+ (M/Mp)^{2/3}], where I is one for white dwarfs with non-relativistic…
Wandering Among Newton Wonders
Donald Lynden-Bell
In the electromagnetic fields t^2 B = b(r/t), E = r x B/t trajectories of non-relativistic charged particles conserve (r-vt)^2. The transformation r'=r/t t'=1/t maps such trajector…
The Newton Wonder in Mechanics
Donald Lynden-Bell
Application of Newton's ideas from "Principia" gives many new results in mechanics. Here we explore the question ``What form of extra force will maintain the magnitude of a vector…
Rotation, Statistical Dynamics and Kinematics of Globular Clusters
Donald Lynden-Bell
Evolution with mass segregation and the evolution of the rotation of cores are both discussed for self-similar core collapse. Evolution with angular velocity proportional to the sq…
Equiangular Spiral Modes of Power Law Disks
D. Lynden-Bell, J. P. S. Lemos
The stability of self-similar power-law disks to non-axially symmetrical disturbances of zero frequency (omega = 0) is discussed. It is established that marginally unstable modes e…
From Quasars to Extraordinary N-body Problems
D. Lynden-Bell
We outline reasoning that led to the current theory of quasars and look at George Contopoulos's place in the long history of the N-body problem. Following Newton we find new exactl…
Instantaneous Inertial Frame but Retarded Electromagnetism in Rotating Relativistic Collapse
J. Katz, D. Lynden-Bell, J. Bicak
Slowly rotating collapsing spherical shells have flat spaces inside and the inertial frames there rotate at omega_s(t) relative to infinity. As first shown by Lindblom & Brill the…
New sources for Kerr and other metrics: rotating relativistic disks with pressure support
C. Pichon, D. Lynden-Bell
Complete sequences of new analytic solutions of Einstein's equations which describe thin super massive disks are constructed. These solutions are derived geometrically. The identif…
An analytic approximation to the isothermal sphere
Priyamvada Natarajan, Donald Lynden-Bell
We present a useful analytic approximation to the solution of the Lane-Emden equation for infinite polytropic index - the isothermal sphere. The optimized expression obtained for t…
Classical Mechanics without Absolute Space
D. Lynden-Bell, J. Katz
A relative mechanics with no absolute space is shown to be equivalent to Newtonian mechanics applied in a universe of zero net angular momentum. Closed spaces in General Relativity…
Wiener Reconstruction of Density, Velocity, and Potential Fields from All-Sky Galaxy Redshift Surveys
Karl Fisher, Ofer Lahav, Yehuda Hoffman +2
We present a new method for recovering the cosmological density, velocity, and potential fields from all-sky redshift catalogues. The method is based on an expansion of the fields…