Radiative corrections with 5D mixed position-/momentum-space propagators

In higher dimensional field theories with compactified dimensions there are three standard ways to do perturbative calculations: (i) by the summation over Kaluza-Klein towers; (ii) by the summation over winding numbers making use of the Poisson-resummation formula; and (iii) by using mixed propagators, where the coordinates of the four infinite dimensions are Fourier-transformed to momentum space while those of the compactified dimension are kept in configuration space. The third method is broadly used in finite temperature field theory calculations. One of its advantages is that one can easily separate the ultraviolet divergent terms of the uncompactified theory from the non-local finite corrections arising from windings around the compact dimensions. In this note we demonstrate the use of this formalism by calculating one-loop self-energy corrections in a 5D theory formulated on the manifold height="14" border="0" style="vertical-align:bottom" width="56" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0003491604000065-si1.gif"> and on the orbifold height="18" border="0" style="vertical-align:bottom" width="91" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0003491604000065-si2.gif">.     

Gravitational field of global monopole with semi-classical effects

We find an exact solution for the space-time of a global monopole by using the vacuum expectation value of the stress energy tensor due to an arbitrary collection of conformal mass less free quantum fields as a source. In a particular situation, the solution is shown to possess an interesting feature like ‘wormholes’ space-time. The monopole exerts no gravitational force on the surrounding matter.     

Arbuzov rearrangement in the 1,3,2-oxazaphosphinane series

Reactions of 2-alkoxy-1,3,2-oxazaphosphinanes (including 3-alkyl derivatives) with methyl and ethyl bromoacetates give two types of Arbuzov rearrangement products (cyclic and acyclic ones). The ratio between their yields is virtually independent of the nature of the substituent in position 3 of the starting reagent, being mainly determined by the nature of the substituent in the phosphorus bound alkoxy group and varying from 96 : 4 to 2 : 98. Acyclic products can be converted into cyclic ones.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1915–1918, September, 2004.     

The first example of direct heterylation of calixpyrrole

1,2,4-Triazine derivatives react with calixpyrrole to give stable nucleophilic addition products.     

Measurement of RLT and ATL in the 4He(e, e’p)3H reaction at pmiss of 130-300 MeV/ c

We have measured the ⁴He(e, eh20/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0">p)³H reaction at missing momenta of 130-300 MeV/c using the three-spectrometer facility at the Mainz microtron MAMI. Data were taken in perpendicular kinematics to allow us to determine the response function R_LT and the asymmetry term A_TL. The data are compared to both relativistic and non-relativistic calculations.     

Synthesis of 4-phenyl-3,4-dihydro-β-carboline

4-Phenyl-3,4-dihydro-h95k4727/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-carboline was prepared using the Bischler—Napieralski reaction on h95k4727/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-phenyltryptamine.Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 486–487, November–December, 2004.This revised version was published online in April 2005 with a corrected cover date.     

Theta Pairs and the Structure of Finite Groups

We introduce the notion of h98378p57/xxlarge952.gif" alt="theta" align="BASELINE" BORDER="0">-pair of a proper subgroup of a finite group and give necessary and sufficient conditions for supersolvability and nilpotence of a finite group. As application, we give a proof to a recent open problem of Skiba in the unsolved problems in group theory.     

Modeling,Mathematical and Numerical Analysis of Electrorheological Fluids

Many electrorheological fluids are suspensions consisting of solid particles and a carrier oil. If such a suspension is exposed to a strong electric field the effective viscosity increases dramatically. In this paper we first derive a model which captures this behaviour. For the resulting system of equations we then prove local in time existence of strong solutions for large data. For these solutions we finally derive error estimates for a fully implicit time-discretization.     

Dielectric relaxation in single crystal NH4H2PO4 in the high-temperature regime

The dispersion curves of the dielectric response in single crystal NH₄H₂PO₄ were obtained in the radio frequency range and below the high-temperature transition at T_p−160 °C. The results reveal dielectric relaxation at low frequency, which is about 10⁵ Hz at 70 °C, and it shifts to higher frequencies (∼3×10⁶ Hz) as the temperature increases. The relaxation frequency was determined from the peak obtained in the imaginary part of the permittivity as well as from the derivative of the real part of the permittivity. The activation energy E_a=0.55 eV, obtained from the relaxation frequency is very close to that derived from the dc conductivity. We suggest that this dielectric relaxation could be due to the proton jump and phosphate reorientation that cause distortion and change the local lattice polarizability inducing dipoles like height="14" border="0" style="vertical-align:bottom" width="45" alt="View the MathML source" title="View the MathML source" src="http://ars.els-cdn.com/content/image/1-s2.0-S0038109804005484-si1.gif">