1,257 research outputs found
Relations for classical communication capacity and entanglement capability of two-qubit operations
Bipartite operations underpin both classical communication and entanglement
generation. Using a superposition of classical messages, we show that the
capacity of a two-qubit operation for error-free entanglement-assisted
bidirectional classical communication can not exceed twice the entanglement
capability. In addition we show that any bipartite two-qubit operation can
increase the communication that may be performed using an ensemble by twice the
entanglement capability.Comment: 4 page
Design and Operation of Gravity or Surface Systems (Chapter 13)
Surface irrigation uses open channel flow to spread water over a field.
The driving force in such systems is gravity and hence the alternate term,
gravity flooding. Once distributed over the surface of the field and after it has
entered the soil, water is often redistributed by forces other than gravity.
Surface irrigation systems generally require a smaller initial investment
than do other types of irrigation systems. However, this is not always the
case, especially if extensive land forming is needed for an efficient system. In
fact, the need for extensive land forming is one of the main reasons why other
types of irrigation systems have been developed
Non-perturbative Heavy Quark Effective Theory
We explain how to perform non-perturbative computations in HQET on the
lattice. In particular the problem of the subtraction of power-law divergences
is solved by a non-perturbative matching of HQET and QCD. As examples, we
present a full calculation of the mass of the b-quark in the combined static
and quenched approximation and outline an alternative way to obtain the B-meson
decay constant at lowest order. Since no excessively large lattices are
required, our strategy can also be applied including dynamical fermions.Comment: 27 pages including figures and tables, latex2e; version published in
JHEP, typos corrected and 1 reference adde
Normal Coordinates Describing Coupled Oscillations in the Gravitational Field
The motion of a local source inducing small oscillations in the gravitational
field is investigated and shown to exhibit pure rotational kinetic energy.
Should the net affect of these slow, revolving oscillations cause large-scale
rotations in spacetime it would certainly result in anomalous celestial
accelerations. When this angular rotational frequency of spacetime is applied
to the anomalous acceleration of the Pioneer 10/11 spacecrafts, the correlation
is promising.Comment: General Relativity and Gravitation Ref.: Ms. No. GERG-D-06-00077R1
accepted for publication October 06, 200
Duality properties of indicatrices of knots
The bridge index and superbridge index of a knot are important invariants in
knot theory. We define the bridge map of a knot conformation, which is closely
related to these two invariants, and interpret it in terms of the tangent
indicatrix of the knot conformation. Using the concepts of dual and derivative
curves of spherical curves as introduced by Arnold, we show that the graph of
the bridge map is the union of the binormal indicatrix, its antipodal curve,
and some number of great circles. Similarly, we define the inflection map of a
knot conformation, interpret it in terms of the binormal indicatrix, and
express its graph in terms of the tangent indicatrix. This duality relationship
is also studied for another dual pair of curves, the normal and Darboux
indicatrices of a knot conformation. The analogous concepts are defined and
results are derived for stick knots.Comment: 22 pages, 9 figure
Heavy quark action on the anisotropic lattice
We investigate the improved quark action on anisotropic lattice as a
potential framework for the heavy quark, which may enable precision computation
of hadronic matrix elements of heavy-light mesons. The relativity relations of
heavy-light mesons as well as of heavy quarkonium are examined on a quenched
lattice with spatial lattice cutoff 1.6 GeV and the
anisotropy . We find that the bare anisotropy parameter tuned for the
massless quark describes both the heavy-heavy and heavy-light mesons within 2%
accuracy for the quark mass , which covers the charm quark
mass. This bare anisotropy parameter also successfully describes the
heavy-light mesons in the quark mass region within the
same accuracy. Beyond this region, the discretization effects seem to grow
gradually. The anisotropic lattice is expected to extend by a factor the
quark mass region in which the parameters in the action tuned for the massless
limit are applicable for heavy-light systems with well controlled systematic
errors.Comment: 11 pages, REVTeX4, 11 eps figure
DNA repair as a human biomonitoring tool: comet assay approaches.
The comet assay offers the opportunity to measure both DNA damage and repair. Various comet assay based methods are available to measure DNA repair activity, but some requirements should be met for their effective use in human biomonitoring studies. These conditions include i) robustness of the assay, ii) sources of inter- and intra-individual variability must be known, iii) DNA repair kinetics should be assessed to optimize sampling timing; and iv) DNA repair in accessible surrogate tissues should reflect repair activity in target tissues prone to carcinogenic effects. DNA repair phenotyping can be performed on frozen and fresh samples, and is a more direct measurement than genomic or transcriptomic approaches. There are mixed reports concerning the regulation of DNA repair by environmental and dietary factors. In general, exposure to genotoxic agents did not change base excision repair (BER) activity, whereas some studies reported that dietary interventions affected BER activity. On the other hand, in vitro and in vivo studies indicated that nucleotide excision repair (NER) can be altered by exposure to genotoxic agents, but studies on other life style related factors, such as diet, are rare. Thus, crucial questions concerning the factors regulating DNA repair and inter-individual variation remain unanswered. Intra-individual variation over a period of days to weeks seems limited, which is favourable for DNA repair phenotyping in biomonitoring studies. Despite this reported low intra-individual variation, timing of sampling remains an issue that needs further investigation. A correlation was reported between the repair activity in easily accessible peripheral blood mononuclear cells (PBMCs) and internal organs for both NER and BER. However, no correlation was found between tumour tissue and blood cells. In conclusion, although comet assay based approaches to measure BER/NER phenotypes are feasible and promising, more work is needed to further optimize their application in human biomonitoring and intervention studie
Ioffe-time distributions instead of parton momentum distributions in description of deep inelastic scattering
We argue that parton distributions in coordinate space provide a more natural
object for nonperturbative methods compared to the usual momentum distributions
in which the physics of different longitudinal distances is being mixed. To
illustrate the advantages of the coordinate space formulation, we calculate the
coordinate space distributions for valence quarks in the proton using the QCD
sum rule approach. A remarkable agreement is found between the calculated and
the experimentally measured u-quark distribution up to light-cone distances
of order fm in the proton rest frame.
The calculation for valence d quarks gives much worse results; the reasons for
this discrepancy are discussed.Comment: 24 pages plus 13 pages with figures, requires epsf.sty, revised
version to appear in Phys.Rev.
Late syn- to post-collisional magmatism in Madagascar: the genesis of the Ambalavao and Maevarano Suites
The East African Orogen involves a collage of Proterozoic microcontinents and arc terranes that became wedged between older cratonic blocks during the assembly of Gondwana. The EdiacaranâCambrian Ambalavao and Maevarano Suites in Madagascar were emplaced during the waning orogenic stages and consist of weakly deformed to undeformed plutonic rocks and dykes of mainly porphyritic granite but also gabbro, diorite and charnockite. U-Pb geochronological data date emplacement of the Ambalavao Suite to between ca. 580 Ma and 540 Ma and the Maevarano Suite to between ca. 537 Ma and 522 Ma. Major and trace element concentrations are consistent with emplacement in a syn- to post-collisional tectonic setting as A-type (anorogenic) suites. Oxygen (ÎŽÂčâžO of 5.27â°â7.45â°) and hafnium (ΔHf(t) of â27.8 to â12.3) isotopic data from plutons in the Itremo and Antananarivo Domains are consistent with incorporation of an ancient crustal source. More primitive ÎŽÂčâžO (5.27â°â5.32â°) and ΔHf(t) (+0.0 to +0.2) isotopic values recorded in samples collected from the Ikalamavony Domain demonstrate the isotopic variation of basement sources present in the Malagasy crust. The Hf isotopic composition of Malagasy zircon are unlike more juvenile EdiacaranâCambrian zircon sources elsewhere in the East African Orogen and, as such, Madagascar represents a distinct and identifiable detrital zircon source region in Phanerozoic sedimentary provenance studies. Taken together, these data indicate that high-T crustal anatexis, crustal assimilation and interaction of crustal material with mantle-derived melts were the processes operating during magma emplacement. This magmatism was coeval with polyphase deformation throughout Madagascar during the amalgamation of Gondwana and magmatism is interpreted to reflect lithospheric delamination of an extensive orogenic plateau.Donnelly B. Archibald, Alan S. Collins, John D. Foden, Justin L. Payne, Peter Holden, ThĂ©odore Razakamanan
Logarithmic scaling in gauge/string correspondence
We study anomalous dimensions of (super)conformal Wilson operators at weak
and strong coupling making use of the integrability symmetry on both sides of
the gauge/string correspondence and elucidate the origin of their
single-logarithmic behavior for long operators/strings in the limit of large
Lorentz spin. On the gauge theory side, we apply the method of the Baxter
Q-operator to identify different scaling regimes in the anomalous dimensions in
integrable sectors of (supersymmetric) Yang-Mills theory to one-loop order and
determine the values of the Lorentz spin at which the logarithmic scaling sets
in. We demonstrate that the conventional semiclassical approach based on the
analysis of the distribution of Bethe roots breaks down in this domain. We work
out an asymptotic expression for the anomalous dimensions which is valid
throughout the entire region of variation of the Lorentz spin. On the string
theory side, the logarithmic scaling occurs when two most distant points of the
folded spinning string approach the boundary of the AdS space. In terms of the
spectral curve for the classical string sigma model, the same configuration is
described by an elliptic curve with two branching points approaching values
determined by the square root of the 't Hooft coupling constant. As a result,
the anomalous dimensions cease to obey the BMN scaling and scale
logarithmically with the Lorentz spin.Comment: 37 pages, 4 figure
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