831 research outputs found
A note on the genus Tocantinsia (Pisces, Nematognathi, Auchenipteridae)
It is argued that the catfish described by MEES (1974) as representing a new genus and a new species of the Auchenipteridae : Tocantinsia depressa, is conspecific with Glanidium piresi A. DE MIRANDA RIBEIRO (1920) and that consequently the former is a junior synonym of the latter. However, the species does not belong in the genus Glanidium, being sufficiently distinct from all other Auchenipteridae to be retained in the separate genus Tocantinsia. Therefore, its correct name is Tocantinsia piresi (A. DE MIRANDA RIBEIRO)
Group Manifold Reduction of Dual N=1 d=10 Supergravity
We perform a group manifold reduction of the dual version of N=1 d=10
supergravity to four dimensions. The effects of the 3- and 4-form gauge fields
in the resulting gauged N=4 d=4 supergravity are studied in particular. The
example of the group manifold SU(2)xSU(2) is worked out in detail, and we
compare for this case the four-dimensional scalar potential with gauged N=4
supergravity.Comment: 22 pages, revised section 3, typos corrected. Published versio
Colloquium: To sea or not to sea - 2nd international colloquium on maritime and fluvial archaeology in the southern North Sea area, Brugge (Belgium), 21-23 September 2006: book of abstracts = Colloquium: Ter zee of niet ter zee - 2de internationaal colloquium over maritieme en fluviale archeologie in het zuidelijke Noordzeegebied, Brugge (België), 21-23 september 2006: book of abstracts
Colloquium Visserij, handel en piraterij: vissers en vissersnederzettingen in en rond het Noordzeegebied in de Middeleeuwen en later, 21-23 November 2003 Museum Walraversijde, Oostende, Belgium = Colloquium Fishery, trade and piracy: fishermen and fishermen's settlements in and around the North Sea area in the Middle Ages and later, 21-23 November 2003 Museum Walraversijde, Oostende, Belgium
De Sitter solutions in N=4 matter coupled supergravity
We investigate the scalar potential of gauged N=4 supergravity with matter.
The extremum in the SU(1,1)/U(1) scalars is obtained for an arbitrary number of
matter multiplets. The constraints on the matter scalars are solved in terms of
an explicit parametrisation of an
SO(6,6+n) element. For the case of six matter multiplets we discuss both
compact and noncompact gauge groups.
In an example involving noncompact groups and four scalars we find a
potential with an absolute minimum and a positive cosmological constant.Comment: 14 page
`Stringy' Newton-Cartan Gravity
We construct a "stringy" version of Newton-Cartan gravity in which the
concept of a Galilean observer plays a central role. We present both the
geodesic equations of motion for a fundamental string and the bulk equations of
motion in terms of a gravitational potential which is a symmetric tensor with
respect to the longitudinal directions of the string. The extension to include
a non-zero cosmological constant is given. We stress the symmetries and
(partial) gaugings underlying our construction. Our results provide a
convenient starting point to investigate applications of the AdS/CFT
correspondence based on the non-relativistic "stringy" Galilei algebra.Comment: 44 page
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