244 research outputs found
Uniform infinite planar triangulation and related time-reversed critical branching process
We establish a connection between the uniform infinite planar triangulation
and some critical time-reversed branching process. This allows to find a
scaling limit for the principal boundary component of a ball of radius R for
large R (i.e. for a boundary component separating the ball from infinity). We
show also that outside of R-ball a contour exists that has length linear in R.Comment: 27 pages, 5 figures, LaTe
Holographic fermions at strong translational symmetry breaking: a Bianchi-VII case study
It is presently unknown how strong lattice potentials influence the fermion
spectral function of the holographic strange metals predicted by the AdS/CFT
correspondence. This embodies a crucial test for the application of holography
to condensed matter experiments. We show that for one particular momentum
direction this spectrum can be computed for arbitrary strength of the effective
translational symmetry breaking potential of the so-called Bianchi-VII geometry
employing ordinary differential equations. Deep in the strange metal regime we
find rather small changes to the single-fermion response computed by the
emergent quantum critical IR, even when the potential becomes relevant in the
infra-red. However, in the regime where holographic quasi-particles occur,
defining a Fermi surface in the continuum, they acquire a finite lifetime at
any finite potential strength. At the transition from irrelevancy to relevancy
of the Bianchi potential in the deep infra-red the quasi-particle remnants
disappear completely and the fermion spectrum exhibits a purely relaxational
behaviour.Comment: 30 pages, 10 figure
Baryon and chiral symmetry breaking
We briefly review the generalized Skyrmion model for the baryon recently
suggested by us. It takes into account the tower of vector and axial mesons as
well as the chiral symmetry breaking. The generalized Skyrmion model provides
the qualitative explanation of the Ioffe's formula for the baryon mass.Comment: 7 pages, Contribution to the Proceedings of the II Russian-Spanish
Congress "Particle and Nuclear Physics at all Scales and Cosmology",
Saint-Petersburg, October 1-4, 201
Four-point correlator of vector currents and electric current susceptibility in holographic QCD
In this work we calculate the four-point correlation function of vector quark
currents of QCD via holographic QCD model. Computing the correlator we take
into account the exchange of vector and axial vector bosons and dilaton in the
bulk. The result is used for calculation of the two-point correlator of
electromagnetic currents in external magnetic field at zero momentum, related
to RHIC experiments, chiral magnetic effect and lattice study. At zero
temperature we find this quantity to be loosely connected with chiral symmetry
breaking and strongly dependent on the confinement properties. Some features of
the AdS/QCD models are also discussed.Comment: 14 pages, 1 figure (v2: references added, typos corrected
More on the Tensor Response of the QCD Vacuum to an External Magnetic Field
In this Letter we discuss a few issues concerning the magnetic susceptibility
of the quark condensate and the Son-Yamamoto (SY) anomaly matching equation. It
is shown that the SY relation in the IR implies a nontrivial interplay between
the kinetic and WZW terms in the chiral Lagrangian. It is also demonstrated
that in a holographic framework an external magnetic field triggers mixing
between scalar and tensor fields. Accounting for this, one may calculate the
magnetic susceptibility of the quark condensate to all orders in the magnetic
field.Comment: 20 pages, 2 figure
Wilson loops in holographic models with a gluon condensate
The aim of this work is to study the holographic dual to the gauge theory
with a nonzero gluon condensate. We check for consistency the holographic way
of describing the condensate and calculate the expectation value of a small
Wilson loop in the presence of the gluon condensate, thus obtaining the
relevant coefficient in the operator product expansion of the small loop in
different holographic models. We also study the effect of the condensate on the
Gross-Ooguri phase transition in the correlator of two circular Wilson loops in
parallel and concentric configurations. In the numerical study of the
concentric case, we find that the phase transition changes its order when the
size of the loops is of order of the gluon condensate. We report this change of
the phase transition order to be a new effect in Wilson loop correlators.Comment: 24 pages, 6 figure
Genetic determinants of complicated pregnancy
The connections of polymorphic variants of the gene of vasoactive hormones with the level of arterial pressure in pregnant women, depending on the development of preeclampsia (PE), have been studie
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