877 research outputs found
Additive Volume of Sets Contained in Few Arithmetic Progressions
A conjecture of Freiman gives an exact formula for the largest volume of a
finite set of integers with given cardinality and doubling . The formula is known to hold when , for some small range
over and for families of structured sets called chains. In this paper we
extend the formula to sets of every dimension and prove it for sets composed of
three segments, giving structural results for the extremal case. A weaker
extension to sets composed of a bounded number of segments is also discussed.Comment: 16 page
On the structure of subsets of an orderable group with some small doubling properties
The aim of this paper is to present a complete description of the structure
of subsets S of an orderable group G satisfying |S^2| = 3|S|-2 and is
non-abelian
Alien Registration- Freiman, John A. (Lagrange, Penobscot County)
https://digitalmaine.com/alien_docs/7753/thumbnail.jp
Quantum effects in the radial thermal expansion of bundles of single-walled carbon nanotubes doped with 4He
The radial thermal expansion (ar) of bundles of single-walled carbon
nanotubes saturated with 4He impurities to the molar concentration 9.4% has
been investigated in the interval 2.5-9.5 K using the dilatometric method. In
the interval 2.1-3.7 K (ar) is negative and is several times higher than the
negative (ar) for pure nanotube bundles. This most likely points to 4He atom
tunneling between different positions in the nanotube bundle system. The excess
expansion was reduced with decreasing 4He concentration.Comment: 4 pages, 1 figure, will be published in Fiz.Nizk Temp. #7, 201
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