3,010,578 research outputs found
SciTech News Volume 70, No. 4 (2016)
Columns and Reports
From the Editor 3
Division News
Science-Technology Division 4
SLA Annual Meeting 2016 Report (S. Kirk Cabeen Travel Stipend Award recipient) 6
Reflections on SLA Annual Meeting (Diane K. Foster International Student Travel Award recipient) 8
SLA Annual Meeting Report (Bonnie Hilditch International Librarian Award recipient)10
Chemistry Division 12
Engineering Division 15
Reflections from the 2016 SLA Conference (SPIE Digital Library Student Travel Stipend recipient)15
Fundamentals of Knowledge Management and Knowledge Services (IEEE Continuing Education Stipend recipient) 17
Makerspaces in Libraries: The Big Table, the Art Studio or Something Else? (by Jeremy Cusker) 19
Aerospace Section of the Engineering Division 21
Reviews
Sci-Tech Book News Reviews 22
Advertisements
IEEE 17
WeBuyBooks.net 2
Super Yang-Mills, division algebras and triality
We give a unified division algebraic description of (D=3, N=1,2,4,8), (D=4,
N=1,2,4), (D=6, N=1,2) and (D=10, N=1) super Yang-Mills theories. A given
(D=n+2, N) theory is completely specified by selecting a pair (A_n, A_{nN}) of
division algebras, A_n, A_{nN} = R, C, H, O, where the subscripts denote the
dimension of the algebras. We present a master Lagrangian, defined over
A_{nN}-valued fields, which encapsulates all cases. Each possibility is
obtained from the unique (O, O) (D=10, N=1) theory by a combination of
Cayley-Dickson halving, which amounts to dimensional reduction, and removing
points, lines and quadrangles of the Fano plane, which amounts to consistent
truncation. The so-called triality algebras associated with the division
algebras allow for a novel formula for the overall (spacetime plus internal)
symmetries of the on-shell degrees of freedom of the theories. We use imaginary
A_{nN}-valued auxiliary fields to close the non-maximal supersymmetry algebra
off-shell. The failure to close for maximally supersymmetric theories is
attributed directly to the non-associativity of the octonions.Comment: 24 pages, 2 figures. Updated to match published version. References
adde
A phase-locked frequency divide-by-3 optical parametric oscillator
Accurate phase-locked 3:1 division of an optical frequency was achieved, by
using a continuous-wave (cw) doubly resonant optical parametric oscillator. A
fractional frequency stability of 2*10^(-17) of the division process has been
achieved for 100s integration time. The technique developed in this work can be
generalized to the accurate phase and frequency control of any cw optical
parametric oscillator.Comment: 4 pages, 5 figures in a postscript file. To appear in a special issue
of IEEE Trans. Instr. & Meas., paper FRIA-2 presented at CPEM'2000
conference, Sydney, May 200
A novel uplink multiple access scheme based on TDS-FDMA
This contribution proposes a novel time-domain synchronous frequency division multiple access (TDS-FDMA) scheme to support multi-user uplink application. A unified frame structure for both single-carrier and multi-carrier transmissions and the corresponding low-complexity receiver design are derived. Compared with standard cyclic prefix based orthogonal frequency division multiple access systems, the proposed TDSFDMA scheme improves the spectral efficiency by about 5% to 10% as well as imposes a similarly low computational complexity, while obtaining a slightly better bit error rate performance over Rayleigh fading channels
The symplectic origin of conformal and Minkowski superspaces
Supermanifolds provide a very natural ground to understand and handle
supersymmetry from a geometric point of view; supersymmetry in and
dimensions is also deeply related to the normed division algebras.
In this paper we want to show the link between the conformal group and
certain types of symplectic transformations over division algebras. Inspired by
this observation we then propose a new\,realization of the real form of the 4
dimensional conformal and Minkowski superspaces we obtain, respectively, as a
Lagrangian supermanifold over the twistor superspace and a
big cell inside it.
The beauty of this approach is that it naturally generalizes to the 6
dimensional case (and possibly also to the 10 dimensional one) thus providing
an elegant and uniform characterization of the conformal superspaces.Comment: 15 pages, references added, minor change
Finite Lorentz Transformations, Automorphisms, and Division Algebras
We give an explicit algebraic description of finite Lorentz transformations
of vectors in 10-dimensional Minkowski space by means of a parameterization in
terms of the octonions. The possible utility of these results for superstring
theory is mentioned. Along the way we describe automorphisms of the two highest
dimensional normed division algebras, namely the quaternions and the octonions,
in terms of conjugation maps. We use similar techniques to define and
via conjugation, via symmetric multiplication, and via
both symmetric multiplication and one-sided multiplication. The
non-commutativity and non-associativity of these division algebras plays a
crucial role in our constructions.Comment: 24 pages, Plain TeX, 2 figures on 1 page submitted separately as
uuencoded compressed tar fil
- âŠ