58 research outputs found
The syntomic regulator for the -theory of fields
No full textWe define complexes analogous to Goncharov's complexes for the K-theory of discrete valuation rings of characteristic zero. Under suitable assumptions in K-theory, there is a map from the cohomology of those complexes to the K-theory of the ring under consideration. In case the ring is a localization of the ring of integers in a number field, there are no assumptions necessary. We compute the composition of our map to the K-theory with the syntomic regulator. The result can be described in terms of a p-adic polylogarithm. Finally, we apply our theory in order to compute the regulator to syntomic cohomology on Beilinson's cyclotomic elements. The result is again given by the p-adic polylogarithm. This last result is related to one by Somekawa and generalizes work by Gros
Hyperbolic tessellations and generators of K <sub>3</sub> for imaginary quadratic fields
Get PDFWe develop methods for constructing explicit generators, modulo torsion, of the K3 -groups of imaginary quadratic number fields. These methods are based on either tessellations of hyperbolic 3 -space or on direct calculations in suitable pre-Bloch groups and lead to the very first proven examples of explicit generators, modulo torsion, of any infinite K3 -group of a number field. As part of this approach, we make several improvements to the theory of Bloch groups for K3 of any field, predict the precise power of 2 that should occur in the Lichtenbaum conjecture at −1 and prove that this prediction is valid for all abelian number fields
Étale cohomology, cofinite generation, and -adic -functions
Get PDFLet p be a prime number. We study certain étale cohomology groups with coefficients associated to a p-adic Artin representation of the Galois group of a number field k. These coefficients are equipped with a modified Tate twist involving a p-adic index. The groups are cofinitely generated, and we determine the additive Euler characteristic. If k is totally real and the representation is even, we study the relation between the behaviour or the value of the p-adic L-function at the point e in its domain, and the cohomology groups with p-adic twist 1-e. In certain cases this gives short proofs of a conjecture by Coates and Lichtenbaum, and the equivariant Tamagawa number conjecture for classical L-functions. For p=2 our results involving p-adic L-functions depend on a conjecture in Iwasawa theory
On K1 of Curves over Global Fields : Bloch’s Conjecture and Wild Kernels
No full textPour X une courbe sur un corps global k, lisse, projective et géométriquement connexe, nous déterminons la Q-structure du groupe de Quillen K1(X) : nous démontrons que dimQ K1(X) ? Q =2r, où r désigne le nombre de places archimédiennes de k (y compris le cas r = 0 pour un corps de fonctions). Cela con?rme une conjecture de Bloch annoncée dans les années 1980. Dans le langage de la K-théorie de Milnor, que nous dé?nissons pour les variétés algébriques via les groupes de Somekawa, le premier K-groupe spécial de Milnor SKM1 (X) est de torsion. Pour la preuve, nous développons une théorie des hauteurs applicable aux K-groupes de Milnor, et nous généralisons l’approche de base de facteurs de Bass-Tate. Une structure plus ?ne de SKM 1 (X) émerge en localisant le corps de base k, et une description explicite de la décomposition correspondante est donnée. En particulier, nous identi?ons un sous-groupe WKl(X):= ker (SKM 1 (X) ? Zl ? Lv SKM 1 (Xv) ? Zl) pour chaque entier rationnel l, nommé noyau sauvage, dont nous croyons qu’il est ?ni.For a smooth projective geometrically connected curve X over a global ?eld k, we determine the Q-structure of its ?rst Quillen K-group K1(X) by showing that dimQ K1(X) ? Q =2r, where r denotes the number of archimedean places of k (including the case r = 0 for k a function ?eld). This con?rms a conjecture of Bloch. In the language of Milnor K-theory, which we de?ne for varieties via Somekawa groups, the ?rst special Milnor K-group SKM 1 (X) is torsion. For the proof, we develop a theory of heights applicable to Milnor K-groups, and generalize the factor basis approach of Bass-Tate. A ?ner structure of SKM 1 (X) emerges when localizing the ground ?eld k, and we give an explicit description of the resulting decomposition. In particular, we identify a potentially ?nite subgroup WKl(X):= ker (SKM 1 (X) ? Zl ? Lv SKM 1 (Xv) ? Zl) for each rational prime l, named wild kernel
Developing a circularity self-assessment tool: a case study for the Dutch plastics industry
No full textThe European Commission published the “EU action plan for the Circular Economy” in 2015, the Dutch government strives for a circular Netherlands before the year 2050 (Rijksoverheid, 2016) and Rotterdam aims for circularity as the norm in 2030 (Rotterdam Circulair, 2018). To reach these goals, set by governmental organisations, change is required in all levels of society: individuals, municipalities, companies and other types of organisations. This master thesis focuses on the role of companies in the transition towards a circular economy. Companies often have limited insights in their circular performance. A current state analysis is needed to set realistic targets and keep track of the progress. Currently, there is a lack of workable tools that facilitate this analysis. For such a tool to contribute to the acceleration of the progress towards a circular economy, it is considered of great importance that it is easy in use and stimulates the user to action. This research developed a self-assessment rubric to create insights in the circular performance of an individual company. A case study was conducted for the Dutch plastics industry. The result was tested in cooperation with three companies and the results proved to generate relevant insights
Appendix to the Paper of Scholl
No full textLet X/Q be a smooth projective (but not necessariy geometrically irreducible) variety, and let χ be a flat proper model of X over Z. Then the image of the map K′∗(χ)⊗Q→K′∗(X)⊗Q=K∗(X)⊗Q (1) is independent of the model χ
Bounding generators for the kernel and cokernel of the tame symbol for curves
No full textLet C be a regular, irreducible curve that is projective over a field. We obtain bounds in terms of the arithmetic genus of C for the generators that are required for the cokernel of the tame symbol, as well as, under a simplifying assumption, its kernel. We briefly discuss a potential application to Chow groups.</p
Conjectures, consequences, and numerical experiments for p-adic Artin L-functions
No full textWe conjecture that the p-adic L-function of a non-trivial irreducible even Artin character over a totally real field is non-zero at all non-zero integers. This implies that a conjecture formulated by Coates and Lichtenbaum at negative integers extends in a suitable way to all positive integers. We also state a conjecture that for certain characters the Iwasawa series underlying the p-adic L-series have no multiple roots except for those corresponding to the zero at s=0 of the p-adic L-function. We provide some theoretical evidence for our first conjecture, and prove both conjectures by means of computer calculations for a large set of characters (and integers where appropriate) over the rationals and over real quadratic fields, thus proving many instances of conjectures by Coates and Lichtenbaum and by Schneider. The calculations and the theoretical evidence also prove that certain p-adic regulators corresponding to 1-dimensional characters for the rational numbers are units in many cases. We also verify Gross' conjecture for the order of the zero of the p-adic L-function at s=0 in many cases. We gather substantial statistical data on the constant term of the underlying Iwasawa series, and propose a model for its behaviour for certain characters
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