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91.
92.
E. Elizalde S. Naftulin S. D. Odintsov 《Zeitschrift fur Physik C Particles and Fields》1993,59(4):617-620
The renormalization structure of two-dimensional quantum gravity is investigated in a covariant gauge. One-loop divergences of the effective action are calculated. All the surface divergent terms are taken into account thus completing previous one-loop calculations of the theory. It is shown that the on-shell effective action contains only surface divergences. The off-shell renormalizability of the theory is discussed and classes of renormalizable dilaton and Maxwell potentials are found. 相似文献
93.
Emilio Aicart Huu Van Tra Lina Andreoli-Ball Donald Patterson 《Journal of solution chemistry》1994,23(11):1183-1201
Expansion coefficients , isothermal compressibilities, thermal pressure coefficients and heat capacities have been measured at 25°C for the cyclohexane+trans-decalin system. An S-shaped composition dependence, positivelnegative for highllow cyclohexane compositions is found for C
p
E
dV
E
/dT and the thermal expansion contribution to C
p
E
namely VT. The thermal motion contribution to C
p
E
, namely C
v
is close to zero. The positive excursion of these mixing quantities at high cyclohexane content is anomalous. Correspondingly, the mixing quantity-VT deviates strongly in this region from the predicted equality with H
E
. The literature and this work show that all these excess quantities behave similarly for cyclohexane mixed with cyclooctane, methylcyclohexane and some highly branched alkanes. The unusual composition dependence of the thermodynamic quantities is consistent with order occurring when any large alkane molecule of globular shape is added to cyclohexane. This is speculatively associated with an interference by the globular alkane with the relatively free rotation of cyclohexane molecules. 相似文献
94.
Emilio Freire Armengol Gasull Antoni Guillamon 《Bulletin des Sciences Mathématiques》2007,131(6):501-517
Given a planar vector field U which generates the Lie symmetry of some other vector field X, we prove a new criterion to control the stability of the periodic orbits of U. The problem is linked to a classical problem proposed by A.T. Winfree in the seventies about the existence of isochrons of limit cycles (the question suggested by the study of biological clocks), already answered by Guckenheimer using a different terminology. We apply our criterion to give upper bounds of the number of limit cycles for some families of vector fields as well as to provide a class of vector fields with a prescribed number of hyperbolic limit cycles. Finally we show how this procedure solves the problem of the hyperbolicity of periodic orbits in problems where other criteria, like the classical one of the divergence, fail. 相似文献
95.
96.
97.
98.
We examine, at a classical level, the features that distinguish dynamically conserved currents from identically conserved ones. Then we prove that, in four spacetime dimensions, the quantum charges corresponding to identically conserved currents always annihilate the vacuum state. We illustrate our discussion with several examples. 相似文献
99.
100.
Emilio Calvo 《International Journal of Game Theory》2008,37(4):533-563
We propose two variations of the non-cooperative bargaining model for games in coalitional form, introduced by Hart and Mas-Colell
(Econometrica 64:357–380, 1996a). These strategic games implement, in the limit, two new NTU-values: the random marginal and
the random removal values. Their main characteristic is that they always select a unique payoff allocation in NTU-games. The
random marginal value coincides with the Consistent NTU-value (Maschler and Owen in Int J Game Theory 18:389–407, 1989) for
hyperplane games, and with the Shapley value for TU games (Shapley in In: Contributions to the theory of Games II. Princeton
University Press, Princeton, pp 307–317, 1953). The random removal value coincides with the solidarity value (Nowak and Radzik
in Int J Game Theory 23:43–48, 1994) in TU-games. In large games we show that, in the special class of market games, the random
marginal value coincides with the Shapley NTU-value (Shapley in In: La Décision. Editions du CNRS, Paris, 1969), and that
the random removal value coincides with the equal split value.
相似文献