1,307 research outputs found
Gravitational cubic interactions for a massive mixed symmetry gauge field
In a recent paper arXiv:1107.1872 cubic gravitational interactions for a
massless mixed symmetry field in AdS space have been constructed. In the
current paper we extend these results to the case of massive field. We work in
a Fradkin-Vasiliev approach and use frame-like gauge invariant description for
massive field which works in (A)dS spaces with arbitrary values of cosmological
constant including flat Minkowski space. In this, massless limit in AdS space
coincides with the results of arXiv:1107.1872 while we show that it is
impossible to switch on gravitational interaction for massless field in dS
space.Comment: 13 page
Interactions between a massless tensor field with the mixed symmetry of the Riemann tensor and a massless vector field
Consistent couplings between a massless tensor field with the mixed symmetry
of the Riemann tensor and a massless vector field are analyzed in the framework
of Lagrangian BRST cohomology. Under the assumptions on smoothness, locality,
Lorentz covariance, and Poincare invariance of the deformations, combined with
the requirement that the interacting Lagrangian is at most second-order
derivative, it is proved that there are no consistent cross-interactions
between a single massless tensor field with the mixed symmetry of the Riemann
tensor and one massless vector field.Comment: LaTeX, 24 page
Interactions of a massless tensor field with the mixed symmetry of the Riemann tensor. No-go results
Non-trivial, consistent interactions of a free, massless tensor field t_{\mu
\nu |\alpha \beta} with the mixed symmetry of the Riemann tensor are studied in
the following cases: self-couplings, cross-interactions with a Pauli-Fierz
field and cross-couplings with purely matter theories. The main results,
obtained from BRST cohomological techniques under the assumptions on
smoothness, locality, Lorentz covariance and Poincar\'{e} invariance of the
deformations, combined with the requirement that the interacting Lagrangian is
at most second-order derivative, can be synthesized into: no consistent
self-couplings exist, but a cosmological-like term; no cross-interactions with
the Pauli-Fierz field can be added; no non-trivial consistent cross-couplings
with the matter theories such that the matter fields gain gauge transformations
are allowed.Comment: for version 3: 45 pages, uses amssymb; shortened version, the three
appendices from version 2 can be found in hep-th/040209
Adiabatic invariants drive rhythmic human motion in variable gravity
Natural human movements are stereotyped. They minimise cost functions that
include energy, a natural candidate from mechanical and physiological points of
view. In time-changing environments, however, motor strategies are modified
since energy is no longer conserved. Adiabatic invariants are relevant
observables in such cases, although they have not been investigated in human
motor control so far. We fill this gap and show that the theory of adiabatic
invariants explains how humans move when gravity varies
BRST cohomological results on the massless tensor field with the mixed symmetry of the Riemann tensor
The basic BRST cohomological properties of a free, massless tensor field with
the mixed symmetry of the Riemann tensor are studied in detail. It is shown
that any non-trivial co-cycle from the local BRST cohomology group can be taken
to stop at antighost number three, its last component belonging to the
cohomology of the exterior longitudinal derivative and containing non-trivial
elements from the (invariant) characteristic cohomology.Comment: 39 page
TB26: Native Bees Associated with the Low-Bush Blueberry in Maine and Eastern Canada
Native bees are particularly important pollinators of lowbush blueberry. Changes in certain cultural practices since the 1930s, however, have caused substantial reductions in the native bee populations. Recent observations, however, have shown that adjustments in these practices can have a beneficial effect on native bees with accompanying increases in their numbers. Collections of native Apoidea were made in various areas of Maine and eastern Canada from 1961 through 1965 to determine the species present and their relative abundance in blueberry fields. Of the 89 species collected, 59 were taken on lowbush blueberry blossoms, and 10 in close association with lowbush blueberry. Species in the families Halictidae and Andrenidae were by far the most numerous (32 and 23 species), followed in decreasing occurrence by species in the families Bombidae, Anthophoridae, Colletidae, and Xylocopidae.https://digitalcommons.library.umaine.edu/aes_techbulletin/1165/thumbnail.jp
Supersymmetric Higher Spin Theories
We revisit the higher spin extensions of the anti de Sitter algebra in four
dimensions that incorporate internal symmetries and admit representations that
contain fermions, classified long ago by Konstein and Vasiliev. We construct
the , Euclidean and Kleinian version of these algebras, as well as the
corresponding fully nonlinear Vasiliev type higher spin theories, in which the
reality conditions we impose on the master fields play a crucial role. The
supersymmetric higher spin theory in , on which we elaborate
further, is included in this class of models. A subset of Konstein-Vasiliev
algebras are the higher spin extensions of the superalgebras
for mod 4 and can be realized using
fermionic oscillators. We tensor the higher superalgebras of the latter kind
with appropriate internal symmetry groups and show that the mod 4
higher spin algebras are isomorphic to those with mod 4. We
describe the fully nonlinear higher spin theories based on these algebras as
well, and we elaborate further on the supersymmetric theory,
providing two equivalent descriptions one of which exhibits manifestly its
relation to the supersymmetric higher spin theory.Comment: 30 pages. Contribution to J. Phys. A special volume on "Higher Spin
Theories and AdS/CFT" edited by M. R. Gaberdiel and M. Vasilie
No cross-interactions among different tensor fields with the mixed symmetry (3,1) intermediated by a vector field
Under the hypotheses of analyticity in the coupling constant, locality,
Lorentz covariance, and Poincare invariance of the deformations, combined with
the preservation of the number of derivatives on each field, the consistent
interactions between a collection of free massless tensor gauge fields with the
mixed symmetry of a two-column Young diagram of the type (3,1) and one Abelian
vector field, respectively a -form gauge field, are addressed. The main
result is that a single mixed symmetry tensor field from the collection gets
coupled to the vector field/-form. Our final result resembles to the well
known fact from General Relativity according to which there is one graviton in
a given world.Comment: 19 page
The Exploitation of Toxic Fish from the Terminal Pleistocene in Maritime Southeast Asia: A Case Study from the Mindoro Archaeological Sites, Philippines
Representatives of the Diodontidae family (porcupinefish) are known to have been fished by prehistoric Indo-Pacific populations; however, the antiquity of the use of this family is thus far unknown. We report here on the presence of Diodontidae in the archaeological sites of Bubog I, II, and Bilat in Mindoro, Philippines, dating back to c. 13,000 BP (Before Present). This evidence demonstrates the early exploitation by islanders of poisonous fish. Every part of porcupinefish can be toxic, but the toxicity is mostly concentrated in some organs, while other parts are edible. The continuous presence of Diodontidae remains throughout the stratigraphic record of these Philippines shell middens suggests that porcupinefish were prepared by human inhabitants of the sites to render them safe for consumption, indicating an advanced cultural knowledge of the preparation needed to separate the toxic principle from the edible parts. This constitutes one of the rare examples of poison processing by humans, aside from the contentious wooden stick poison applicator from Border Cave (South Africa)
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