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191.
If (, M)is a factorization system on a category C, we define new classes of maps as follows: a map f:AB is in if each of its pullbacks lies in (that is, if it is stably in ), and is in M
* if some pullback of it along an effective descent map lies in M(that is, if it is locally in M). We find necessary and sufficient conditions for (, M
*) to be another factorization system, and show that a number of interesting factorization systems arise in this way. We further make the connexion with Galois theory, where M
*is the class of coverings; and include self-contained modern accounts of factorization systems, descent theory, and Galois theory. 相似文献
192.
Andrew Ranicki 《K-Theory》1989,3(2):163-195
The cobordism groups of quadratic Poincaré complexes in an additive category with involution
are identified with the Wall L-groups of quadratic forms and formations in
, generalizing earlier work for modules over a ring with involution by avoiding kernels and cokernels. 相似文献
193.
194.
Gerald Dunn 《K-Theory》1995,9(6):591-605
We show that theK-theory of a Waldhausen categoryC with anA-ring structure is anA ring spectrum. If theA structure onC supports anE
n
structure, so thatBC group completes to ann-fold loop space, thenK (C) is anE
n
ring spectrum. In particular, theK-theory of the category of crossedG-sets,G a finite group, is anE
2 ring spectrum. 相似文献
195.
We define a ribbon category , depending on a parameter β, which encompasses Cautis, Kamnitzer and Morrison's spider category, and describes for the monoidal category of representations of generated by exterior powers of the vector representation and their duals. We identify this category with a direct limit of quotients of a dual idempotented quantum group , proving a mixed version of skew Howe duality in which exterior powers and their duals appear at the same time. We show that the category gives a unified natural setting for defining the colored link invariant (for ) and the colored HOMFLY-PT polynomial (for β generic). 相似文献
196.
N. Rodriguez-Sanchez T.W. Schultz M.T.D. Cronin 《SAR and QSAR in environmental research》2013,24(11):963-977
This study outlines how a combination of and in vitro data can be used to define the applicability domain of selected structural alerts within the protein binding profilers of the Organisation for Economic Co-operation (OECD) Quantitative Structure–Activity Relationship (QSAR) Toolbox. Thirty chemicals containing a cyclic moiety were profiled for reactivity using the OECD and Optimised Approach based on Structural Indices Set (OASIS) protein binding profilers. The profiling results identified 22 of the chemicals as being reactive towards proteins. Analysis of the experimentally data showed 19 of these chemicals to be reactive. Subsequent analysis allowed refinements to be suggested to improve the applicability domain of the structural alerts investigated. The accurate definition of the applicability domain for structural alerts within in silico profilers is important due to their use in chemical category in predictive and regulatory toxicology. 相似文献
197.
Gonçalo Tabuada 《Advances in Mathematics》2009,221(4):1122-1143
We construct a Quillen model structure on the category of spectral categories, where the weak equivalences are the symmetric spectra analogue of the notion of equivalence of categories. 相似文献
198.
In this article we carry on the study of the fundamental category (Goubault and Raussen, Dihomotopy as a tool in state space
analysis. In: Rajsbaum, S. (ed.) LATIN 2002: Theoretical Informatics. Lecture Notes in Computer Science, vol. 2286, Cancun,
Mexico, pp. 16–37, Springer, Berlin Heidelberg New York, 2002; Goubault, Homology, Homotopy Appl., 5(2): 95–136, 2003) of a partially ordered topological space (Nachbin, Topology and Order, Van Nostrand, Princeton, 1965; Johnstone, Stone Spaces, Cambridge University Press, Cambridge, MA, 1982), as arising in e.g. concurrency theory (Fajstrup et al., Theor. Comp. Sci. 357: 241–278, 2006), initiated in (Fajstrup et al., APCS, 12(1): 81–108, 2004). The “algebra” of dipaths modulo dihomotopy (the fundamental category) of such a po-space is essentially finite in a number
of situations. We give new definitions of the component category that are more tractable than the one of Fajstrup et al. (APCS,
12(1): 81–108, 2004), as well as give definitions of future and past component categories, related to the past and future models of Grandis (Theory
Appl. Categ., 15(4): 95–146, 2005). The component category is defined as a category of fractions, but it can be shown to be equivalent to a quotient category,
much easier to portray. A van Kampen theorem is known to be available on fundamental categories (Grandis, Cahiers Topologie
Géom. Différentielle Catég., 44: 281–316, 2003; Goubault, Homology, Homotopy Appl., 5(2): 95–136, 2003), we show in this paper a similar theorem for component categories (conjectured in Fajstrup et al. (APCS, 12(1): 81–108,
2004). This proves useful for inductively computing the component category in some circumstances, for instance, in the case of
simple PV mutual exclusion models (Goubault and Haucourt, A practical application of geometric semantics to static analysis
of concurrent programs. In: Abadi, M., de Alfaro, L. (eds.) CONCUR 2005 – Concurrency Theory: 16th International Conference,
San Francisco, USA, August 23–26. Lecture Notes in Computer Science, vol. 3653, pp. 503–517, Springer, Berlin Heidelberg New
York, 2005), corresponding to partially ordered subspaces of R
n
minus isothetic hyperrectangles. In this last case again, we conjecture (and give some hints) that component categories enjoy
some nice adjunction relations directly with the fundamental category.
相似文献
199.
Lev V. Zilbergleit 《Acta Appl Math》1999,56(2-3):301-320
Singularities of solutions of graded differential equations as filtrations are studied. Symbols and the transfer operator associated with the h-adic filtration are computed. The condition that the transfer operator is a differential operator over the characteristic manifold of codimension 1 for this filtration is given. The Dirac operator is introduced by using the De Broglie principle: singularities of wave-like solutions move as material points. Use of the transfer operator associated with the h-adic filtration implies an invariant definition of the Pauli operator. A natural parallel translation arises as quantum analog of the Levi-Civita connection. 相似文献
200.
Takeshi Yamazaki 《Mathematical Logic Quarterly》2000,46(1):105-110
In this paper, we generalize a result of Brown and Simpson [1] to prove that RCA0+Π0∞‐BCT is conservative over RCA0 with respect to the set of formulae in the form ∃!Xφ(X), where φ is arithmetical. We also consider the conservation of Π00∞‐BCT over Σb1‐NIA+∇b1‐CA. 相似文献