1,920 research outputs found
A Meta-Algorithm for Creating Fast Algorithms for Counting ON Cells in Odd-Rule Cellular Automata
We develop a meta-algorithm that, given a polynomial (in one or more
variables), and a prime p, produces a fast (logarithmic time) algorithm that
takes a positive integer n and outputs the number of times each residue class
modulo p appears as a coefficient when the polynomial is raised to the power n
and the coefficients are read modulo p.Comment: 8 pages, accompanied by a Maple package, and numerous input and
output files that can be gotten from
http://www.math.rutgers.edu/~zeilberg/mamarim/mamarimhtml/CAcount.htm
Universal quantum computation with unlabeled qubits
We show that an n-th root of the Walsh-Hadamard transform (obtained from the
Hadamard gate and a cyclic permutation of the qubits), together with two
diagonal matrices, namely a local qubit-flip (for a fixed but arbitrary qubit)
and a non-local phase-flip (for a fixed but arbitrary coefficient), can do
universal quantum computation on n qubits. A quantum computation, making use of
n qubits and based on these operations, is then a word of variable length, but
whose letters are always taken from an alphabet of cardinality three.
Therefore, in contrast with other universal sets, no choice of qubit lines is
needed for the application of the operations described here. A quantum
algorithm based on this set can be interpreted as a discrete diffusion of a
quantum particle on a de Bruijn graph, corrected on-the-fly by auxiliary
modifications of the phases associated to the arcs.Comment: 6 page
Multiple planar coincidences with N-fold symmetry
Planar coincidence site lattices and modules with N-fold symmetry are well
understood in a formulation based on cyclotomic fields, in particular for the
class number one case, where they appear as certain principal ideals in the
corresponding ring of integers. We extend this approach to multiple
coincidences, which apply to triple or multiple junctions. In particular, we
give explicit results for spectral, combinatorial and asymptotic properties in
terms of Dirichlet series generating functions.Comment: 13 pages, two figures. For previous related work see math.MG/0511147
and math.CO/0301021. Minor changes and references update
On the Brownian gas: a field theory with a Poissonian ground state
As a first step towards a successful field theory of Brownian particles in
interaction, we study exactly the non-interacting case, its combinatorics and
its non-linear time-reversal symmetry. Even though the particles do not
interact, the field theory contains an interaction term: the vertex is the
hallmark of the original particle nature of the gas and it enforces the
constraint of a strictly positive density field, as opposed to a Gaussian free
field. We compute exactly all the n-point density correlation functions,
determine non-perturbatively the Poissonian nature of the ground state and
emphasize the futility of any coarse-graining assumption for the derivation of
the field theory. We finally verify explicitly, on the n-point functions, the
fluctuation-dissipation theorem implied by the time-reversal symmetry of the
action.Comment: 31 page
Multiqubit symmetric states with high geometric entanglement
We propose a detailed study of the geometric entanglement properties of pure
symmetric N-qubit states, focusing more particularly on the identification of
symmetric states with a high geometric entanglement and how their entanglement
behaves asymptotically for large N. We show that much higher geometric
entanglement with improved asymptotical behavior can be obtained in comparison
with the highly entangled balanced Dicke states studied previously. We also
derive an upper bound for the geometric measure of entanglement of symmetric
states. The connection with the quantumness of a state is discussed
A Fascinating Polynomial Sequence arising from an Electrostatics Problem on the Sphere
A positive unit point charge approaching from infinity a perfectly spherical
isolated conductor carrying a total charge of +1 will eventually cause a
negatively charged spherical cap to appear. The determination of the smallest
distance ( is the dimension of the unit sphere) from the point
charge to the sphere where still all of the sphere is positively charged is
known as Gonchar's problem. Using classical potential theory for the harmonic
case, we show that is equal to the largest positive zero of a
certain sequence of monic polynomials of degree with integer
coefficients which we call Gonchar polynomials. Rather surprisingly,
is the Golden ratio and the lesser known Plastic number. But Gonchar
polynomials have other interesting properties. We discuss their factorizations,
investigate their zeros and present some challenging conjectures.Comment: 12 pages, 6 figures, 1 tabl
Masses of Astrometrically-Discovered and Imaged Binaries: G 78-28AB and GJ 231.1BC
The Stellar Planet Survey (STEPS) is an ongoing astrometric search for giant
planets and brown dwarfs around a sample of ~30 M-dwarfs. We have discovered
several low-mass companions by measuring the motion of our target stars
relative to their reference frames. The highest mass discovery thus far is G
78-28B, a companion to the M-dwarf G 78-28A. The orbital period is 4.18 +/-
0.03 y, the system mass is 0.565 +/- 0.055 Msolar, and the semi-major axis is
2.19 +/- 0.10 AU. Imaging observations with the Keck laser guide star adaptive
optics (LGSAO) and the Palomar AO instruments resolved the system and also
yielded JHK-band delta magnitudes. We use the orbital solution, light ratios,
and mass-luminosity relationships to derive component masses of MA = 0.370 +/-
0.034 Msolar and MB = 0.195 +/- 0.021 Msolar. G 78-28B is of type M4 V based
upon its colors and mass. We also discovered GJ 231.1C, a companion to GJ
231.1B, with STEPS and imaged the companion with LGSAO and Palomar AO, but the
orbital period is longer than our observing baseline; thus the system
parameters are less constrained. In GJ 231.1BC the masses are MB = 0.25 +/-
0.06 Msolar and MC =0.12 +/- 0.02 Msolar. The inferred spectral type of GJ
231.1C is M5 V. We demonstrate the results of the current state of mass
estimation techniques with our data.Comment: 25 pages, 8 figures, accepted for Ap
Revenue divergence and competitive balance in a divisional sports league
The North American model of resource allocation in professional sports leagues is adapted for English (association) football. The theoretical relationship between revenue and competitive balance is shown to be robust with respect to changes in teams’ objectives and labour market conditions. Empirical revenue functions are reported for 1926-1999. These indicate a shift in the composition of demand favouring big-city teams and an increase in the sensitivity of revenue to performance. An analysis of match results in the FA Cup competition suggests an increase in competitive imbalance between teams at different levels of the league’s divisional hierarchy, as the theory suggests
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