286 research outputs found
Peripheral fillings of relatively hyperbolic groups
A group theoretic version of Dehn surgery is studied. Starting with an
arbitrary relatively hyperbolic group we define a peripheral filling
procedure, which produces quotients of by imitating the effect of the Dehn
filling of a complete finite volume hyperbolic 3--manifold on the
fundamental group . The main result of the paper is an algebraic
counterpart of Thurston's hyperbolic Dehn surgery theorem. We also show that
peripheral subgroups of 'almost' have the Congruence Extension Property and
the group is approximated (in an algebraic sense) by its quotients obtained
by peripheral fillings. Various applications of these results are discussed.Comment: The difference with the previous version is that Proposition 3.2 is
proved for quasi--geodesics instead of geodesics. This allows to simplify the
exposition in the last section. To appear in Invent. Mat
The electrical properties of coating obtained by vacuum arc deposition
AbstractThis paper investigates the electrical properties of the coating based on TiâCâB system. The coating was obtained by vacuum-arc method by spraying of multi compound cathode prepared by reactive hot pressing of Ti, carbon black and amorphous B powder mixture.The electrical conductivity of the coating was measured in temperature range of 10â320K which was about Ď=4.8¡103Ίâ1cmâ1 in the entire temperature range. The carrier concentration measured was about n=1¡1022 cmâ3. The charge carriersâ mobility varies between 10 and â7 and changes sign at temperature about T=225K
Low-Molecular Weight Cow Colostrum Components in Functional Nutrition
Background: The concept of functional nutrition has been actively developed in recent years. LMWCC contains biologically active compounds of natural origin and can be promising components of functional nutrition.Methods: Wistar rats (intact, rats with Cu-induced toxicosis and rats with Cu-induced toxicosis, who received LMWCC per os in different doses of 0.01, 0.05, 0.1, 1, 2, 3 mg / 100 g of body weight of the animal). The effect of low-molecular weight components of cow colostrum (LMWCC) have been studied on the some physiological and biochemical parameters (body weight, temperature, ability to perform work, activity of aspartate aminotransferase, alanine aminotransferase, cholesterol, triacylglycerides, creatinine, albumin, gamma-glutamyltransferase and lipid hydroperoxides) in experimental animals with Cu -induced toxicosis.Results: It was found that LMWCC in small doses (0.05-0.1 mg / 100 g of weight) restored the growth rate, body temperature and partially working capacity in the test "swimming with a load" of animals with Cu-induced toxicosis. Restoration of physiological parameters in animals with Cu-induced toxemia correlated with activation of the antioxidant enzyme glutathione peroxidase and a decrease in serum hydroperoxides in blood serum.It was suggested that LMWCC can be promising components of functional nutrition for various toxicoses.Conclusions: LMWCC has antioxidant properties in relatively small doses (0.05-0.1 mg / 100 g of weight). Restoration of the physiological characteristics of animals with Cu-induced toxicosis correlates with the elimination of oxidative stress. Large doses of 1 mg / 100 g of body weight and more manifest pro-oxidant properties
A complete solution of a Constrained System: SUSY Monopole Quantum Mechanics
We solve the quantum mechanical problem of a charged particle on S^2 in the
background of a magnetic monopole for both bosonic and supersymmetric cases by
constructing Hilbert space and realizing the fundamental operators obeying
complicated Dirac bracket relations in terms of differential operators. We find
the complete energy eigenfunctions. Using the lowest energy eigenstates we
count the number of degeneracies and examine the supersymmetric structure of
the ground states in detail.Comment: 20 pages including the title, prepared in JHEP forma
Higher Spins from Tensorial Charges and OSp(N|2n) Symmetry
It is shown that the quantization of a superparticle propagating in an N=1,
D=4 superspace extended with tensorial coordinates results in an infinite tower
of massless spin states satisfying the Vasiliev unfolded equations for free
higher spin fields in flat and AdS_4 N=1 superspace. The tensorial extension of
the AdS_4 superspace is proved to be a supergroup manifold OSp(1|4). The model
is manifestly invariant under an OSp(N|8) (N=1,2) superconformal symmetry. As a
byproduct, we find that the Cartan forms of arbitrary Sp(2n) and OSp(1|2n)
groups are GL(2n) flat, i.e. they are equivalent to flat Cartan forms up to a
GL(2n) rotation. This property is crucial for carrying out the quantization of
the particle model on OSp(1|4) and getting the higher spin field dynamics in
super AdS_4, which can be performed in a way analogous to the flat case.Comment: LaTeX, 21 page (JHEP style), misprints corrected, added comments on
the relation of results of hep-th/0106149 with hep-th/9904109 and
hep-th/9907113, references adde
Topological Superfluid in one-dimensional Ultracold Atomic System with Spin-Orbit Coupling
We propose a one-dimensional Hamiltonian which supports Majorana
fermions when -wave superfluid appears in the ultracold atomic
system and obtain the phase-separation diagrams both for the
time-reversal-invariant case and time-reversal-symmetry-breaking case. From the
phase-separation diagrams, we find that the single Majorana fermions exist in
the topological superfluid region, and we can reach this region by tuning the
chemical potential and spin-orbit coupling . Importantly, the
spin-orbit coupling has realized in ultracold atoms by the recent experimental
achievement of synthetic gauge field, therefore, our one-dimensional ultra-cold
atomic system described by is a promising platform to find the
mysterious Majorana fermions.Comment: 5 papers, 2 figure
Electromagnetic form factors of charged and neutral kaons in an extended vector-meson-dominance model
A model is developed for electromagnetic form factors of the charged and
neutral K-mesons. The formalism is based on ChPT Lagrangians with vector
mesons. The form factors, calculated without fitting parameters, are in a good
agreement with experiment for space-like and time-like photon momenta.
Contribution of the two-kaon channels to the muon anomalous magnetic moment
a_\mu is calculated.Comment: 23 pages, 11 figures, accepted for publication in Eur. Phys. J.
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
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