45 research outputs found
Spacetime scale-invariant super-p-brane actions on enlarged superspaces and the geometry of kappa-symmetry
We use the additional variables of suitably enlarged superspaces to write new
actions for extended objects, with kappa-symmetry, in such a way that the
tension emerges from them as an integration constant. Our actions correspond to
the spacetime scale-invariant ones previously considered by Bergshoeff et al.
once the worldvolume forms introduced there are reinterpreted in terms of
fields associated with the coordinates of the enlarged superspaces. It is shown
that the kappa-symmetry of the new actions is given by a certain type of right
local transformations of the extended superspace groups. Further, we also show
that the enlarged superspaces that allow for strictly invariant Wess-Zumino
terms also lead to strict kappa-invariance i.e., the Lagrangian itself (not
only the action) is both supersymmetry- and kappa-invariant.Comment: 23 pages, no figures. A clarifying comment and a reference adde
Contractions of Filippov algebras
We introduce in this paper the contractions of -Lie (or
Filippov) algebras and show that they have a semidirect
structure as their Lie algebra counterparts. As an example, we compute
the non-trivial contractions of the simple Filippov algebras. By
using the \.In\"on\"u-Wigner and the generalized Weimar-Woods contractions of
ordinary Lie algebras, we compare (in the simple case)
the Lie algebras Lie (the Lie algebra of inner endomorphisms
of ) with certain contractions
and of
the Lie algebra Lie associated with .Comment: plain latex, 36 pages. A few misprints corrected. This v3 is actually
v2 (v1 had been replaced by itself by error). To appear in J. Math. Phy
Generalized curvature and the equations of D=11 supergravity
It is known that, for zero fermionic sector, the bosonic equations of
Cremmer-Julia-Scherk eleven-dimensional supergravity can be collected in a
compact expression which is a condition on the curvature of the generalized
connection. Here we peresent the equation which collects all the bosonic
equations of D=11 supergravity when the gravitino is nonvanishing.Comment: 8 pages, plain latex. A few numerical factors corrected. To appear in
Phys. Lett.
On BPS preons, generalized holonomies and D=11 supergravities
We develop the BPS preon conjecture to analyze the supersymmetric solutions
of D=11 supergravity. By relating the notions of Killing spinors and BPS
preons, we develop a moving G-frame method (G=GL(32,R), SL(32,R) or Sp(32,R))
to analyze their associated generalized holonomies. As a first application we
derive here the equations determining the generalized holonomies of k/32
supersymmetric solutions and, in particular, those solving the necessary
conditions for the existence of BPS preonic (31/32) solutions of the standard
D=11 supergravity. We also show that there exist elementary preonic solutions,
i.e. solutions preserving 31 out of 32 supersymmetries in a Chern--Simons type
supergravity. We present as well a family of worldvolume actions describing the
motion of pointlike and extended BPS preons in the background of a D'Auria-Fre
type OSp(1|32)-related supergravity model. We discuss the possible implications
for M-theory.Comment: 11 pages, RevTeX Typos corrected, a short note and references adde
On the absence of BPS preonic solutions in IIA and IIB supergravities
We consider the present absence of 31 out of 32 supersymmetric solutions in
supergravity i.e., of solutions describing BPS preons. A recent result
indicates that (bosonic) BPS preonic solutions do not exist in type IIB
supergravity. We reconsider this analysis by using the G-frame method, extend
it to the IIA supergravity case, and show that there are no (bosonic) preonic
solutions for type IIA either. For the classical D=11 supergravity no
conclusion can be drawn yet, although the negative IIA results permit
establishing the conditions that preonic solutions would have to satisfy. For
supergravities with `stringy' corrections, the existence of BPS preonic
solutions remains fully open.Comment: plain latex, 12 pages Minor misprints corrected. Published in JHEP 09
(2006) 00
BPS states in M-theory and twistorial constituents
We provide a complete algebraic description of BPS states in M-theory in
terms of primary constituents that we call BPS preons. We argue that any BPS
state preserving of the 32 supersymmetries is a composite of (32-k) BPS
preons. In particular, the BPS states corresponding to the basic M2 and M5
branes are composed of 16 BPS preons. By extending the M-algebra to a
generalized D=11 conformal superalgebra we relate the BPS preons
with its fundamental representation, the D=11 supertwistors.Comment: 4 pages. Refs. updated, two cosmetic changes, to appear in PR