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1.
Natale Paolo Vinai 《manuscripta mathematica》2004,115(3):299-311
We prove that the arithmetic degree of a graded or local ring A is bounded above by the arithmetic degree of any of its associated graded rings with respect to ideal I in A. In particular, if Spec(A) is equidimensional and has an embedded component (i.e., A has an embedded associated prime ideal), then the normal cone of Spec(A) along V(I) has an embedded component too. This extends a result of W. M. Ruppert about embedded components of the tangent cone.Mathematics Subject Classification (2000): Primary 13H15, 13A30; Secondary 13D45, 14Q99 相似文献
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For a given two-dimensional surface μ, we studi invariants for oriented links in μ×[0,1] which generalize the two-variable
HOMFLY polynomials when μ is the 2-disk. These invariants are connected to multiparameter quantum groups whose special properties
are discussed.
Si studiano gli invarianti dei nodi in spazi del tipo μ×[0,1], dove μ è una superficie. Questi invarianti generalizzano gli
invarianti di HOMFLY.
(Conferenza tenuta dal Prof. P. Cotta-Ramusino il 16 maggio 1991) 相似文献
(Conferenza tenuta dal Prof. P. Cotta-Ramusino il 16 maggio 1991) 相似文献
5.
Paolo Aluffi 《Rendiconti del Circolo Matematico di Palermo》1938,62(1):3-26
We obtain a precise relation between the Chern–Schwartz–MacPherson class of a subvariety of projective space and the Euler characteristics of its general linear sections. In the case of a hypersurface, this leads to simple proofs of formulas of Dimca–Papadima and Huh for the degrees of the polar map of a homogeneous polynomial, extending these formula to any algebraically closed field of characteristic \(0\), and proving a conjecture of Dolgachev on ‘homaloidal’ polynomials in the same context. We generalize these formulas to subschemes of higher codimension in projective space. We also describe a simple approach to a theory of ‘polynomial Chern classes’ for varieties endowed with a morphism to projective space, recovering properties analogous to the Deligne–Grothendieck axioms from basic properties of the Euler characteristic. We prove that the polynomial Chern class defines homomorphisms from suitable relative Grothendieck rings of varieties to \(\mathbb{Z }[t]\). 相似文献
6.
We prove that there is no functorial universal finite type invariant for braids in Σ×I if the genus of Σ is positive. To cite this article: P. Bellingeri, L. Funar, C. R. Acad. Sci. Paris, Ser. I 338 (2004). 相似文献
7.
Paolo De Lucia J. D. Maitland Wright 《Rendiconti del Circolo Matematico di Palermo》1991,40(3):442-452
Dopo aver dato una definizione di parte convessa di un gruppo topologico, si stabilisce una condizione affinchè il condominio
di una misura sia convesso. 相似文献
8.
Francesco Catoni Roberto Cannata Paolo Zampetti 《Advances in Applied Clifford Algebras》2006,16(2):85-101
It is known that complex numbers can be associated with plane Euclidean geometry and their functions are successfully used
for studying extensions of Euclidean geometry, i.e., non-Euclidean geometries and surfaces differential geometry.
In this paper we begin to study the constant curvature spaces associated with the geometry generated by commutative elliptic-quaternions
and we show how the “mathematics” they generate allows us to introduce these spaces and obtain the geodesic equations without
developing a complete mathematical apparatus as the one developed for Riemannian geometry. 相似文献
9.
We derive the Kramers equation, namely, the Fokker-Planck equation for an oscillator, from a completely deterministic picture. The oscillator is coupled to a “booster”, i.e., a deterministic system in a fully chaotic state, wherein diffusion is derived from the sensitive dependence of chaos on initial conditions and friction is a consequence of the linear response of the booster to the action exerted on it by the oscillator. To deal with the Hamiltonian nature of the system of interest and of its coupling to the booster, we extend the earlier theoretical derivation of macroscopic transport coefficients from deterministic dynamics. We show that the frequency of the oscillator can be tuned to the microscopic frequencies of the booster without affecting the canonical nature of the “macroscopic” statistics. The theoretical predictions are supported by numerical simulations. 相似文献
10.
J. C. S. Moraes E. M. Telles F. C. Cruz A. Scalabrin D. Pereira C. Garelli N. Ioli A. Moretti F. Strumia 《International Journal of Infrared and Millimeter Waves》1991,12(12):1475-1486
We report the discovery of 57 new fir laser lines from13CD3OH molecule optically pumped by a waveguide CO2 laser of 300 MHz tunability. For all lines, precise frequency offset measurements between the CO2 line center and the center of the absorbing13CD3OH line were performed using the transferred Lamb-Dip technique. We have also measured directly the frequency of seven FIR laser lines by heterodyning with already known laser lines. We present a complete list of all known laser lines (134) and frequency measurements (24) for this molecule.Work supported by CNPq, FAPESP, FAEP-Brasil, and CNR-Italia 相似文献