2,758 research outputs found
Electroweak phase transition in technicolor
Several phenomenologically viable walking technicolor models have been
proposed recently. I demonstrate that these models can have first order
electroweak phase transitions, which are sufficiently strong for electroweak
baryogenesis. Strong dynamics can also lead to several separate transitions at
the electroweak scale, with the possibility of a temporary restoration and an
extra breaking of the electroweak symmetry. First order phase transitions will
produce gravitational waves, which may be detectable at future experiments.Comment: 6 pages, 4 figures. Talk at PASCOS 2010 conference, Valencia, 19-23
July 201
Information completeness in Nelson algebras of rough sets induced by quasiorders
In this paper, we give an algebraic completeness theorem for constructive
logic with strong negation in terms of finite rough set-based Nelson algebras
determined by quasiorders. We show how for a quasiorder , its rough
set-based Nelson algebra can be obtained by applying the well-known
construction by Sendlewski. We prove that if the set of all -closed
elements, which may be viewed as the set of completely defined objects, is
cofinal, then the rough set-based Nelson algebra determined by a quasiorder
forms an effective lattice, that is, an algebraic model of the logic ,
which is characterised by a modal operator grasping the notion of "to be
classically valid". We present a necessary and sufficient condition under which
a Nelson algebra is isomorphic to a rough set-based effective lattice
determined by a quasiorder.Comment: 15 page
Representation of Nelson Algebras by Rough Sets Determined by Quasiorders
In this paper, we show that every quasiorder induces a Nelson algebra
such that the underlying rough set lattice is algebraic. We
note that is a three-valued {\L}ukasiewicz algebra if and only if
is an equivalence. Our main result says that if is a Nelson
algebra defined on an algebraic lattice, then there exists a set and a
quasiorder on such that .Comment: 16 page
Hydrogen Atom in Relativistic Motion
The Lorentz contraction of bound states in field theory is often appealed to
in qualitative descriptions of high energy particle collisions. Surprisingly,
the contraction has not been demonstrated explicitly even in simple cases such
as the hydrogen atom. It requires a calculation of wave functions evaluated at
equal (ordinary) time for bound states in motion. Such wave functions are not
obtained by kinematic boosts from the rest frame. Starting from the exact
Bethe-Salpeter equation we derive the equal-time wave function of a
fermion-antifermion bound state in QED, i.e., positronium or the hydrogen atom,
in any frame to leading order in alpha. We show explicitly that the bound state
energy transforms as the fourth component of a vector and that the wave
function of the fermion-antifermion Fock state contracts as expected.
Transverse photon exchange contributes at leading order to the binding energy
of the bound state in motion. We study the general features of the
corresponding fermion-antifermion-photon Fock states, and show that they do not
transform by simply contracting. We verify that the wave function reduces to
the light-front one in the infinite momentum frame.Comment: 20 pages, 10 figures; v2: some changes in discussion, accepted for
publication in Phys.Rev.
Sulfobutyl Ether b-Cyclodextrin (SBE-b-CD) in Eyedrops Improves the Tolerability of a Topically Applied Pilocarpine Prodrug in Rabbits
This is the publisher's version, also available electronically from http://dx.doi.org/10.1089/jop.1995.11.95The effects of a novel, modified β-cyclodextrin (SBE4-β-CD; a variably substituted sulfobutyl ether with an average degree of substitution of four) on eye irritation and miotic response of an ophthalmically applied pilocarpine prodrug, O,O'-dipropionyl-(1,4-xylylene) bispilocarpate, in albino rabbits were studied. Compared to the commercial pilocarpine eyedrop solution (163 mM, equivalent to 3.4% pilocarpine), 12 - 24 mM pilocarpine prodrug solutions (equivalent to 0.5 - 1.0% pilocarpine, respectively) decreased peak miotic intensity (Imax) and increased the time to reach peak (tmax), but did not significantly affect values for the area under the miosis versus time curves (AUC), i.e. 12 - 24 mM pilocarpine prodrug appeared to be equivalent to 163 mM pilocarpine. Ocularly applied 12 - 24 mM pilocarpine prodrug solutions, however, were more irritating than a commercial pilocarpine eyedrop solution. Coadministered SBE4-β-CD significantly decreased the eye irritation of the pilocarpine prodrug solutions. Coadministered SBE4-β-CD did not affect the miotic response of prodrug solution when the molar ratio of SBE4-β-CD to prodrug was low. However, increasing the molar ratio of SBE4-β-CD to prodrug decreased the Imax and AUC values. The results show that eye irritation of the pilocarpine prodrug is prevented by levels of SBE4-β-CD that do not affect the apparent ocular absorption of the prodrug
Cold Collision Frequency Shift in Two-Dimensional Atomic Hydrogen
We report a measurement of the cold collision frequency shift in atomic
hydrogen gas adsorbed on the surface of superfluid 4He at T<=90 mK. Using
two-photon electron and nuclear magnetic resonance in 4.6 T field we separate
the resonance line shifts due to the dipolar and exchange interactions, both
proportional to surface density sigma. We find the clock shift Delta v_c =
-1.0(1)x10^-7 Hz cm^-2 x sigma, which is about 100 times smaller than the value
predicted by the mean field theory and known scattering lengths in the 3D case.Comment: 4 pages, 3 figure
Integrin and dystrophin associated adhesion protein complexes during regeneration of shearing-type muscle injury
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Cloud-base vertical velocity statistics: a comparison between an atmospheric mesoscale model and remote sensing observations
The statistics of cloud-base vertical velocity simulated by the non-hydrostatic mesoscale model AROME are compared with Cloudnet remote sensing observations at two locations: the ARM SGP site in Central Oklahoma, and the DWD observatory at Lindenberg, Germany. The results show that, as expected, AROME significantly underestimates the variability of vertical velocity at cloud-base compared to observations at their nominal resolution; the standard deviation of vertical velocity in the model is typically 4-6 times smaller than observed, and even more during the winter at Lindenberg. Averaging the observations to the horizontal scale corresponding to the physical grid spacing of AROME (2.5 km) explains 70-80% of the underestimation by the model. Further averaging of the observations in the horizontal is required to match the model values for the standard deviation in vertical velocity. This indicates an effective horizontal resolution for the AROME model of at least 4 times the physically-defined grid spacing. The results illustrate the need for special treatment of sub-grid scale variability of vertical velocities in kilometer-scale atmospheric models, if processes such as aerosol-cloud interactions are to be included in the future
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