6,859 research outputs found
The arithmetical rank of the edge ideals of graphs with pairwise disjoint cycles
We prove that, for the edge ideal of a graph whose cycles are pairwise
vertex-disjoint, the arithmetical rank is bounded above by the sum of the
number of cycles and the maximum height of its associated primes
The minimal cellular resolutions of the edge ideals of forests
We present an explicit construction of a minimal cellular resolution for the
edge ideals of forests, based on discrete Morse theory. In particular, the
generators of the free modules are subsets of the generators of the modules in
the Lyubeznik resolution. This procedure allows to ease the computation of the
graded Betti numbers and the projective dimension
Cohomological dimension and arithmetical rank of some determinantal ideals
Let be a non-generic matrix of linear forms in a
polynomial ring. For large classes of such matrices, we compute the
cohomological dimension (cd) and the arithmetical rank (ara) of the ideal
generated by the -minors of . Over an algebraically closed
field, any -matrix of linear forms can be written in the
Kronecker-Weierstrass normal form, as a concatenation of scroll, Jordan and
nilpotent blocks. B\u{a}descu and Valla computed when
is a concatenation of scroll blocks. In this case we compute
and extend these results to concatenations of Jordan
blocks. Eventually we compute and
in an interesting mixed case, when contains both Jordan and scroll blocks.
In all cases we show that is less than the arithmetical
rank of the determinantal ideal of a generic matrix
La dialettica probatoria a confronto con la prova scientifica e neuroscientifica nel processo penale.
L'oggetto di questo elaborato insiste su di un profilo non usuale negli studi della disciplina probatoria, ovvero quello della epistemologia della prova. In particolare, andremo a ricostruire il percorso dell'affermazione della dialettica probatoria come criterio cardine dell'epistemologia processuale, e a verificarne il grado di resistenza di fronte alle sfide dettate dall'utilizzo di conoscenze scientifiche e tecnologiche sempre più complesse all'interno delle aule dei tribunali
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