2,715 research outputs found
Metabolic and immunohistochemical assessment of endocrine pancreatic function after orthotopic multivisceral transplantation
Rational three-spin string duals and non-anomalous finite size effects
We determine by a one line computation the one-loop conformal dimension and
the associated non-anomalous finite size correction for all operators dual to
spinning strings of rational type having three angular momenta (J_1,J_2,J_3) on
S^5. Finite size corrections are conjectured to encode information about string
sigma model loop corrections to the spectrum of type IIB superstrings on
AdS_5xS^5. We compare our result to the zero-mode contribution to the leading
quantum string correction derived for the stable three-spin string with two out
of the three spin labels identical and observe agreement. As a side result we
clarify the relation between the Bethe root description of three-spin strings
of the type (J,J',J') with respectively J>J' and J<J'.Comment: 15 pages, v2: comparison to string theory changed, references added,
v3: textual modifications and title change
High frequency resonant experiments in Fe molecular clusters
Precise resonant experiments on Fe magnetic clusters have been
conducted down to 1.2 K at various tranverse magnetic fields, using a
cylindrical resonator cavity with 40 different frequencies between 37 GHz and
110 GHz. All the observed resonances for both single crystal and oriented
powder, have been fitted by the eigenstates of the hamiltonian . We have identified the
resonances corresponding to the coherent quantum oscillations for different
orientations of spin S = 10.Comment: to appear in Phys.Rev. B (August 2000
Wrapped branes with fluxes in 8d gauged supergravity
We study the gravity dual of several wrapped D-brane configurations in
presence of 4-form RR fluxes partially piercing the unwrapped directions. We
present a systematic approach to obtain these solutions from those without
fluxes. We use D=8 gauged supergravity as a starting point to build up these
solutions. The configurations include (smeared) M2-branes at the tip of a G_2
cone on S^3 x S^3, D2-D6 branes with the latter wrapping a special Lagrangian
3-cycle of the complex deformed conifold and an holomorphic sphere in its
cotangent bundle T^*S^2, D3-branes at the tip of the generalized resolved
conifold, and others obtained by means of T duality and KK reduction. We
elaborate on the corresponding N=1 and N=2 field theories in 2+1 dimensions.Comment: 32 pages, LateX, v2: minor changes, reference added, v3: section
3.5.2 improve
Dorey's Rule and the q-Characters of Simply-Laced Quantum Affine Algebras
Let Uq(ghat) be the quantum affine algebra associated to a simply-laced
simple Lie algebra g. We examine the relationship between Dorey's rule, which
is a geometrical statement about Coxeter orbits of g-weights, and the structure
of q-characters of fundamental representations V_{i,a} of Uq(ghat). In
particular, we prove, without recourse to the ADE classification, that the rule
provides a necessary and sufficient condition for the monomial 1 to appear in
the q-character of a three-fold tensor product V_{i,a} x V_{j,b} x V_{k,c}.Comment: 30 pages, latex; v2, to appear in Communications in Mathematical
Physic
Inherently safer design and optimization of intensified separation processes for furfural production
Heavy Quark Spin Symmetry and Heavy Baryons: Electroweak Decays
Heavy quark spin symmetry is discussed in the context of single and doubly
heavy baryons. A special attention is paid to the constraints/simplifications
that this symmetry imposes on the non-relativistic constituent quark model wave
functions and on the b->c semileptonic decays of these hadrons.Comment: Presented at the 21st European Conference on Few-Body Problems in
Physics, Salamanca, Spain, 30 August - 3 September 201
Relaxation and Landau-Zener experiments down to 100 mK in ferritin
Temperature-independent magnetic viscosity in ferritin has been observed from
2 K down to 100 mK, proving that quantum tunneling plays the main role in these
particles at low temperature. Magnetic relaxation has also been studied using
the Landau-Zener method making the system crossing zero resonant field at
different rates, alpha=dH/dt, ranging from 10^{-5} to 10^{-3} T/s, and at
different temperatures, from 150 mK up to the blocking temperature. We propose
a new Tln(Delta H_{eff}/tau_0 alpha) scaling law for the Landau-Zener
probability in a system distributed in volumes, where Delta H_{eff} is the
effective width of the zero field resonance.Comment: 13 pages, 4 postscript figure
Quantum dynamics of crystals of molecular nanomagnets inside a resonant cavity
It is shown that crystals of molecular nanomagnets exhibit enhanced magnetic
relaxation when placed inside a resonant cavity. Strong dependence of the
magnetization curve on the geometry of the cavity has been observed, providing
evidence of the coherent microwave radiation by the crystals. A similar
dependence has been found for a crystal placed between Fabry-Perot
superconducting mirrors. These observations open the possibility of building a
nanomagnetic microwave laser pumped by the magnetic field
Spiky strings and single trace operators in gauge theories
We consider single trace operators of the form O_{m_1 ... m_n} = tr D_+^{m_1}
F ... D_+^{m_n} F which are common to all gauge theories. We argue that, when
all m_i are equal and large, they have a dual description as strings with
cusps, or spikes, one for each field F. In the case of N=4 SYM, we compute the
energy as a function of angular momentum by finding the corresponding solutions
in AdS_5 and compare with a 1-loop calculation of the anomalous dimension. As
in the case of two spikes (twist two operators), there is agreement in the
functional form but not in the coupling constant dependence. After that, we
analyze the system in more detail and find an effective classical mechanics
describing the motion of the spikes. In the appropriate limit, it is the same
(up to the coupling constant dependence) as the coherent state description of
linear combinations of the operators O_{m_1 ... m_n} such that all m_i are
equal on average. This agreement provides a map between the operators in the
boundary and the position of the spikes in the bulk. We further suggest that
moving the spikes in other directions should describe operators with
derivatives other than D_+ indicating that these ideas are quite generic and
should help in unraveling the string description of the large-N limit of gauge
theories.Comment: 23 pages, 5 figures. v2: References and comments adde
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