59 research outputs found
Theories with Memory
Dimensionally reduced supersymmetric theories retain a great deal of
information regarding their higher dimensional origins. In superspace, this
"memory" allows us to restore the action governing a reduced theory to that
describing its higher-dimensional progenitor. We illustrate this by restoring
four-dimensional N=4 Yang-Mills to its six-dimensional parent, N=(1,1)
Yang-Mills. Supersymmetric truncation is introduced into this framework and
used to obtain the N=1 action in six dimensions. We work in light-cone
superspace, dealing exclusively with physical degrees of freedom.Comment: 18 pages, reference adde
Light-cone gravity in dS
We derive a closed form expression for the light-cone Lagrangian describing
pure gravity on a four-dimensional de Sitter background. We provide a
perturbative expansion, of this Lagrangian, to cubic order in the fields.Comment: 11 page
Factorization of cubic vertices involving three different higher spin fields
We derive a class of cubic interaction vertices for three higher spin fields,
with integer spins , , , by closing
commutators of the Poincar\'e algebra in four-dimensional flat spacetime. We
find that these vertices exhibit an interesting factorization property which
allows us to identify off-shell perturbative relations between them.Comment: 7 page
Maximal supergravity and the quest for finiteness
We show that N = 8 supergravity may possess an even larger symmetry than
previously believed. Such an enhanced symmetry is needed to explain why this
theory of gravity exhibits ultraviolet behaviour reminiscent of the finite N =
4 Yang-Mills theory. We describe a series of three steps that leads us to this
result.Comment: 7 pages, Honorable Mention - Gravity Research Foundation 201
Gravity and Yang-Mills theory
Three of the four forces of Nature are described by quantum Yang-Mills
theories with remarkable precision. The fourth force, gravity, is described
classically by the Einstein-Hilbert theory. There appears to be an inherent
incompatibility between quantum mechanics and the Einstein-Hilbert theory which
prevents us from developing a consistent quantum theory of gravity. The
Einstein-Hilbert theory is therefore believed to differ greatly from Yang-Mills
theory (which does have a sensible quantum mechanical description). It is
therefore very surprising that these two theories actually share close
perturbative ties. This article focuses on these ties between Yang-Mills theory
and the Einstein-Hilbert theory. We discuss the origin of these ties and their
implications for a quantum theory of gravity.Comment: 6 pages, based on contribution to GRF 2010, to appear in a special
edition of IJMP
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