42 research outputs found
From bubbles to foam: dilute to dense evolution of hadronic wave function at high energy
We derive the evolution of a hadronic light cone wave function with energy at
weak coupling. Our derivation is valid both in the high and the low partonic
density limit, and thus encompasses both the JIMWLK and the KLWMIJ evolution.
The hadronic wave function is shown to evolve by the action of the
Bogoliubov-type operator, which diagonalizes on the soft gluon sector the
light-cone hamiltonian in the presence of an arbitrary valence charge density.
We find explicitly the action of this operator on the soft as well as the
valence degrees of freedom of the theory.Comment: 30 page
Type II pp-wave Matrix Models from Point-like Gravitons
The BMN Matrix model can be regarded as a theory of coincident M-theory
gravitons, which expand by Myers dielectric effect into the 2-sphere and
5-sphere giant graviton vacua of the theory. In this note we show that, in the
same fashion, Matrix String theory in Type IIA pp-wave backgrounds arises from
the action for coincident Type IIA gravitons. In Type IIB, we show that the
action for coincident gravitons in the maximally supersymmetric pp-wave
background gives rise to a Matrix model which supports fuzzy 3-sphere giant
graviton vacua with the right behavior in the classical limit. We discuss the
relation between our Matrix model and the Tiny Graviton Matrix theory of
hep-th/0406214.Comment: 18 page
Odderon and seven Pomerons: QCD Reggeon field theory from JIMWLK evolution
We reinterpret the JIMWLK/KLWMIJ evolution equation as the QCD Reggeon field
theory (RFT). The basic "quantum Reggeon field" in this theory is the unitary
matrix which represents the single gluon scattering matrix. We discuss the
peculiarities of the Hilbert space on which the RFT Hamiltonian acts. We
develop a perturbative expansion in the RFT framework, and find several
eigenstates of the zeroth order Hamiltonian. The zeroth order of this
perturbation preserves the number of - channel gluons. The eigenstates have
a natural interpretation in terms of the - channel exchanges. Studying the
single - channel gluon sector we find the eigenstates which include the
reggeized gluon and five other colored Reggeons. In the two ( - channel)
gluon sector we study only singlet color exchanges. We find five charge
conjugation even states. The bound state of two reggeized gluons is the
standard BFKL Pomeron. The intercepts of the other Pomerons in the large
limit are where is the intercept of the BFKL
Pomeron, but their coupling in perturbation theory is suppressed by at least
relative to the double BFKL Pomeron exchange. For the Pomeron
we find . We also find three charge
conjugation odd exchanges, one of which is the unit intercept
Bartels-Lipatov-Vacca Odderon, while another one has an interecept greater than
unity. We explain in what sense our calculation goes beyond the standard
BFKL/BKP calculation. We make additional comments and discuss open questions in
our approach.Comment: 58 pages, 4 figures, Extended version. To appear in JHE
On the worldsheet theories of strings dual to free large N gauge theories
We analyze in detail some properties of the worldsheet of the closed string
theories suggested by Gopakumar to be dual to free large N SU(N) gauge theories
(with adjoint matter fields). We use Gopakumar's prescription to translate the
computation of space-time correlation functions to worldsheet correlation
functions for several classes of Feynman diagrams, by explicit computations of
Strebel differentials. We compute the worldsheet operator product expansion in
several cases and find that it is consistent with general worldsheet conformal
field theory expectations. A peculiar property of the construction is that in
several cases the resulting worldsheet correlation functions are non-vanishing
only on a sub-space of the moduli space (say, for specific relations between
vertex positions). Another strange property we find is that for a conformally
invariant space-time theory, the mapping to the worldsheet does not preserve
the special conformal symmetries, so that the full conformal group is not
realized as a global symmetry on the worldsheet (even though it is, by
construction, a symmetry of all integrated correlation functions).Comment: 60 pages, 17 figures, latex. v2: Added references and a minor
correctio
Integrability of Type II Superstrings on Ramond-Ramond Backgrounds in Various Dimensions
We consider type II superstrings on AdS backgrounds with Ramond-Ramond flux
in various dimensions. We realize the backgrounds as supercosets and analyze
explicitly two classes of models: non-critical superstrings on AdS_{2d} and
critical superstrings on AdS_p\times S^p\times CY. We work both in the
Green--Schwarz and in the pure spinor formalisms. We construct a one-parameter
family of flat currents (a Lax connection) leading to an infinite number of
conserved non-local charges, which imply the classical integrability of both
sigma-models. In the pure spinor formulation, we use the BRST symmetry to prove
the quantum integrability of the sigma-model. We discuss how classical
\kappa-symmetry implies one-loop conformal invariance. We consider the addition
of space-filling D-branes to the pure spinor formalism.Comment: LaTeX2e, 56 pages, 1 figure, JHEP style; v2: references added, typos
fixed in some equations; v3: typos fixed to match the published versio
BPS Operators in N=4 SYM: Calogero Models and 2D Fermions
A connection between the gauge fixed dynamics of protected operators in
superconformal Yang-Mills theory in four dimensions and Calogero systems is
established. This connection generalizes the free Fermion description of the
chiral primary operators of the gauge theory formed out of a single complex
scalar to more general operators. In particular, a detailed analysis of
protected operators charged under an su(1|1)contained in psu(2,2|4) is carried
out and a class of operators is identified, whose dynamics is described by the
rational super-Calogero model. These results are generalized to arbitrary BPS
operators charged under an su(2|3) of the superconformal algebra. Analysis of
the non-local symmetries of the super-Calogero model is also carried out, and
it is shown that symmetry for a large class of protected operators is a
contraction of the corresponding Yangian algebra to a loop algebra.Comment: 29 pages, 3 figure
Branes, Anti-Branes and Brauer Algebras in Gauge-Gravity duality
We propose gauge theory operators built using a complex Matrix scalar which
are dual to brane-anti-brane systems in , in the zero
coupling limit of the dual Yang-Mills. The branes involved are half-BPS giant
gravitons. The proposed operators dual to giant-anti-giant configurations
satisfy the appropriate orthogonality properties. Projection operators in
Brauer algebras are used to construct the relevant multi-trace Matrix
operators. These are related to the ``coupled representations'' which appear in
2D Yang-Mills theory. We discuss the implications of these results for the
quantum mechanics of a complex matrix model, the counting of non-supersymmetric
operators and the physics of brane-anti-brane systems. The stringy exclusion
principle known from the properties of half-BPS giant gravitons, has a new
incarnation in this context. It involves a qualitative change in the map
between brane-anti-brane states to gauge theory operators. In the case of a
pair of sphere giant and anti-giant this change occurs when the sum of the
magnitudes of their angular momenta reaches .Comment: 52 pages, 10 figure
QCD Reggeon Field Theory for every day: Pomeron loops included
We derive the evolution equation for hadronic scattering amplitude at high
energy. Our derivation includes the nonlinear effects of finite partonic
density in the hadronic wave function as well as the effect of multiple
scatterings for scattering on dense hadronic target. It thus includes Pomeron
loops. It is based on the evolution of the hadronic wave function derived in
\cite{foam}. The kernel of the evolution equation defines the second quantized
Hamiltonian of the QCD Reggeon Field Theory, beyond the limits
considered so far. The two previously known limits of the evolution: dilute
target (JIMWLK limit) and dilute projectile (KLWMIJ limit) are recovered
directly from our final result. The Hamiltonian is applicable for the
evolution of scattering amplitude for arbitrarily dense hadronic
projectiles/targets - from "dipole-dipole" to "nucleus-nucleus" scattering
processes.Comment: 35 pages, 5 figure
Noncritical M-Theory in 2+1 Dimensions as a Nonrelativistic Fermi Liquid
We claim that the dynamics of noncritical string theories in two dimensions
is related to an underlying noncritical version of M-theory, which we define in
terms of a double-scaled nonrelativistic Fermi liquid in 2+1 dimensions. After
reproducing Type 0A and 0B string theories as solutions, we study the natural
M-theory vacuum. The vacuum energy of this solution can be evaluated exactly,
its form suggesting a duality to the Debye model of phonons in a melting solid,
and a possible topological nature of the theory. The physical spacetime is
emergent in this theory, only for states that admit a hydrodynamic description.
Among the solutions of the hydrodynamic equations of motion for the Fermi
surface, we find families describing the decay of one two-dimensional string
theory into another via an intermediate M-theory phase.Comment: 47 pages, 1 figure; v2: typos corrected, references adde