2,161 research outputs found
On the origin of quantum mechanics
Action at distance in Newtonian physics is replaced by finite propagation
speeds in classical post--Newtonian physics. As a result, the differential
equations of motion in Newtonian physics are replaced by functional
differential equations, where the delay associated with the finite propagation
speed is taken into account. Newtonian equations of motion, with
post--Newtonian corrections, are often used to approximate the functional
differential equations. Are the finite propagation speeds the origin of the
quantum mechanics? In this work a simple atomic model based on a functional
differential equation which reproduces the quantized Bohr atomic model is
presented. As straightforward application of the result the fine structure of
the hydrogen atom is approached.Comment: 16 pages, 1 figure in EPS forma
Aligned Spins: Orbital Elements, Decaying Orbits, and Last Stable Circular Orbit to high post-Newtonian Orders
In this article the quasi-Keplerian parameterisation for the case that spins
and orbital angular momentum in a compact binary system are aligned or
anti-aligned with the orbital angular momentum vector is extended to 3PN
point-mass, next-to-next-to-leading order spin-orbit, next-to-next-to-leading
order spin(1)-spin(2), and next-to-leading order spin-squared dynamics in the
conservative regime. In a further step, we use the expressions for the
radiative multipole moments with spin to leading order linear and quadratic in
both spins to compute radiation losses of the orbital binding energy and
angular momentum. Orbital averaged expressions for the decay of energy and
eccentricity are provided. An expression for the last stable circular orbit is
given in terms of the angular velocity type variable .Comment: 30 pages, 2 figures, v2: update to match published versio
Diffractive orbits in isospectral billiards
Isospectral domains are non-isometric regions of space for which the spectra
of the Laplace-Beltrami operator coincide. In the two-dimensional Euclidean
space, instances of such domains have been given. It has been proved for these
examples that the length spectrum, that is the set of the lengths of all
periodic trajectories, coincides as well. However there is no one-to-one
correspondence between the diffractive trajectories. It will be shown here how
the diffractive contributions to the Green functions match nevertheless in a
''one-to-three'' correspondence.Comment: 20 pages, 6 figure
Apparent Superluminal Behavior
The apparent superluminal propagation of electromagnetic signals seen in
recent experiments is shown to be the result of simple and robust properties of
relativistic field equations. Although the wave front of a signal passing
through a classically forbidden region can never move faster than light, an
attenuated replica of the signal is reproduced ``instantaneously'' on the other
side of the barrier. The reconstructed signal, causally connected to the
forerunner rather than the bulk of the input signal, appears to move through
the barrier faster than light.Comment: 8 pages, no figure
Numerical treatment of the hyperboloidal initial value problem for the vacuum Einstein equations. III. On the determination of radiation
We discuss the issue of radiation extraction in asymptotically flat
space-times within the framework of conformal methods for numerical relativity.
Our aim is to show that there exists a well defined and accurate extraction
procedure which mimics the physical measurement process. It operates entirely
intrisically within \scri^+ so that there is no further approximation
necessary apart from the basic assumption that the arena be an asymptotically
flat space-time. We define the notion of a detector at infinity by idealising
local observers in Minkowski space. A detailed discussion is presented for
Maxwell fields and the generalisation to linearised and full gravity is
performed by way of the similar structure of the asymptotic fields.Comment: LaTeX2e,13 pages,2 figure
Charge Fluctuations in the Edge States of N-S hybrid Nano-Structures
In this work we show how to calculate the equilibrium and non-equilibrium
charge fluctuations in a gated normal mesoscopic conductor which is attached to
one normal lead and one superconducting lead. We then consider an example where
the structure is placed in a high magnetic field, such that the transport is
dominated by edge states. We calculate the equilibrium and non-equilibrium
charge fluctuations in the gate, for a single edge state, comparing our results
to those for the same system, but with two normal leads. We then consider the
specific example of a quantum point contact and calculate the charge
fluctuations in the gate for more than one edge state.Comment: 4 pages with 1 figure. In published version the high magnetic field
dynamics of the holes is treated incorrectly. An erratum is in preparatio
Sommerfeld's quantum condition of action and the spectra of Schwarzschild black hole
If the situation of quantum gravity nowadays is nearly the same as that of
the quantum mechanics in it's early time of Bohr and Sommerfeld, then a first
step study of the quantum gravity from Sommerfeld's quantum condition of action
might be helpful. In this short paper the spectra of Schwarzschild black
hole(SBH) in quasi-classical approach of quantum mechanics is given. We find
the quantum of area, the quantum of entropy and the Hawking evaporation will
cease as the black hole reaches its ground state.Comment: 7 pages, no figures, submitted to Classical and Quantum Gravit
Dynamics of a Tonks-Girardeau gas released from a hard-wall trap
We study the expansion dynamics of a Tonks-Girardeau gas released from a hard
wall trap. Using the Fermi-Bose map, the density profile is found analytically
and shown to differ from that one of a classical gas in the microcanonical
ensemble even at macroscopic level, for any observation time larger than a
critical time. The relevant time scale arises as a consequence of
fermionization.Comment: 4 pages, 6 figure
- …