This paper presents explicit expressions for the mean sojourn times in a multi-stage tandem queue, with Poisson arrival and general service times, served by a s,ingle server with a cyclic switching rule, M/GI-G2-"'GN/l. The expressions are derived using the results of the two-stage tandem queue, M/GI-G2/1, already considered by some authors and the well-known Pollaczek-Khintchine formula. With ...

Perlick’s classification of (3 + 1)-dimensional spherically symmetric and static spacetimes (M, η = − 1 V dt + g) for which the classical Bertrand theorem holds [Perlick V 1992 Class. Quantum Grav. 9 1009] is revisited. For any Bertrand spacetime (M, η) the term V (r) is proven to be either the intrinsic Kepler– Coulomb or the harmonic oscillator potential on its associated Riemannian 3manifold...

Emittance growth due to intrabeam scattering (IBS) is a major limitation for high energy high density accelerators. The reachable maximum particle density depends strongly on how IBS can be compensated for by electron cooling (EC). Hence calculations of the growth rates of the horizontal and vertical emittances
̇h,v/ h,v and of the (longitudinal) momentum spread
̇ / due to IBS are necessary for...

R. H. Siemann,(‘)t D. G. Cassel,(‘)t G. J. Feldman, (‘It M. S. Alam,(3) R. Aleksan,c2) W. B. Atwood,@) J. Bartelt,c2) J. J. Bisognano,c4) J. R. Boyce,14) D. B. Cline,(‘) G. Coignet,(‘) P. S. Drell,(‘) A. M. Eisner,(‘) A. Fridman,c2) A. A. Garren,(‘) P. Grosse-Wiesmann,(2) D. G. Hitlin,cg) S.-O. Holmgren,(“) H. Kagen,@‘) N. Katayama,c3) H. Koiso,(12) N. B. Mistry,(‘) T Nakada (I31 P. J. Oddone, ...

let $g$ be a graph and let $m_{ij}(g)$, $i,jge 1$, be the number of edges $uv$ of $g$ such that ${d_v(g), d_u(g)} = {i,j}$. the {em $m$-polynomial} of $g$ is introduced with $displaystyle{m(g;x,y) = sum_{ile j} m_{ij}(g)x^iy^j}$. it is shown that degree-based topological indices can be routinely computed from the polynomial, thus reducing the problem of their determination in each particular ca...