Lecturer: Prof. Nelson Braga
Affiliation: Federal University of Rio de Janeiro,
Brazil
Abstract:
It is by now well known that the AdS/CFT
duality provides an interesting way of
calculating anomalous dimensions at high
spin, for a gauge theory at strong coupling.
A high spin operator, made of adjoint fields,
is represented by (or dual to) a rotating
open string in anti-de Sitter space. The
anomalous dimension shows up, in the
string side of the correspondence, simply
as the difference between string energy
and spin. On the other hand it is also know
that it is possible to introduce matter
degrees of freedom - fields in the
fundamental representation of the gauge
group - in the AdS/CFT duality by
introducing probe (flavour) branes. This
approach leads to a nice description of
meson states. So, a natural question to be
asked is : can one calculate the anomalous
dimension for operators in the fundamental
representation, like a quark anti-quark,
using AdS/CFT? This question will be the
main issue of this seminar. We will see that
the presence of an energy scale makes it a
non trivial task the identification of a
quantity representing, in the string side, the
dimension of the gauge theory operator.
Serching for the solution to this problem,
we found a new entry in the dictionary of
AdS/CFT: the anomalous dimension at
high spin is proportional to the string proper
length. Also, we found strong indications
that, in the case of a non conformal duality,
the operator properties are obtained from
measurements made by a local observer
(not sensible to energy scales) in the anti-
de Sitter space, while the description of the
states comes from a coordinate time
observer. (reference: JHEP 1408, 104
(2014) at ArXiv:1405.7388)
Additional details of the upcoming Joint Seminars
in Theoretical High Energy Physics can be found
on the following link