1,721,058 research outputs found
GENERIC DERIVATIONS ON ALGEBRAICALLY BOUNDED STRUCTURES
No full textLet K be an algebraically bounded structure, and let T be its theory. If T is model complete, then the theory of K endowed with a derivation, denoted by Tδ, has a model completion. Additionally, we prove that if the theory T is stable/NIP then the model completion of Tδ is also stable/NIP. Similar results hold for the theory with several derivations, either commuting or non-commuting
A note on exponential polynomials
No full textWe investigate the zero sets of complex exponential polynomials in one variable with only one iteration. We characterize when such polynomials have the same zero set in terms of the radical ideals. Moreover we give a bound on the multiplicity of zeros
Trend decennale della prestazione nella Pallavolo maschile
No full textVengono analizzati i dati di performance tecnico-tattica delle squadre che hanno vinto il campionato Nazionale di pallavolo dall’anno 2000/01 al 2010/11 per un totale di 288 partite di Lega pallavolo Serie A Maschile. Sono stati presi in considerazione come indicatori di performance i dati riguardanti i fondamentali di gioco quali Attacco, Ricezione, Battuta e Muro e alcuni indici derivati. Saranno evidenziati i parametri che negli anni sono rimasti costanti (come i Punti ottenuti in Attacco) e quelli che hanno dimostrato una crescita come i punti acquisiti in Battuta o un calo del trend come nelle Ricezioni eseguite perfettamente. Sono state evidenziate le variabili che hanno dimostrato differenze significative dei valori negli anni come l’Errore in Battuta. Vengono tratte delle conclusioni sull’andamento negli anni delle performance tecnico – tattiche che hanno caratterizzato il Campionato italiano di Serie A Maschile
Relative Pfaffian closure for Definably Complete Baire Structures
Full text linkSpeissegger proved that the Pfaffian closure of an o-
minimal expansion of the real field is o-minimal. Here we give a
first order version of this result: having introduced the notion of
definably complete Baire structure, we define the relative Pfaf-
fian closure of an o-minimal structure inside a definably complete
Baire structure, and we prove its o-minimality. We derive effec-
tive bounds on some topological invariants of sets definable in
the Pfaffian closure of an o-minimal expansion of the real field
Algebraic entropy for amenable semigroup actions
Full text linkWe introduce two notions of algebraic entropy for actions of cancellative right amenable semigroups S on discrete abelian groups A by endomorphisms; they extend the classical algebraic entropy for endomorphisms of abelian groups, corresponding to the case S=N. We investigate the fundamental properties of the algebraic entropy and compute it in several examples, paying special attention to the case when S is an amenable group. For actions of cancellative right amenable monoids on torsion abelian groups, we prove the so called Addition Theorem. In the same setting, we see that a Bridge Theorem connects the algebraic entropy with the topological entropy of the dual action by means of Pontryagin duality, so that we derive an Addition Theorem for the topological entropy of actions of cancellative left amenable monoids on totally disconnected compact abelian groups
Generic solutions of equations with iterated exponentials
No full textWe study solutions of exponential polynomials over the complex field. Assuming Schanuel’s Conjecture we prove that certain polynomials of the form p(z, ez, eez, eeez) = 0 have generic solutions in C
Theorems of the Complement
No full textThis is an expository paper on a Theorem of the Complement, due to
Wilkie, and its generalisations. Wilkie (Sel Math (NS) 5:397–421, 1999) gave
necessary and sufficient conditions for an expansion of the real field by C-infinity
functions to be o-minimal. Karpinski and Macintyre (Sel Math (NS) 5:507–516,
1999) weakened the original smoothness hypotheses of Wilkie’s theorem. Here
we exhibit the proof of a generalised Wilkie’s result, where we further weaken
the smoothness assumptions and show that the proof can be carried out not only
over the real numbers but more generally in a non-Archimedean context, i.e. for
definably complete Baire structures, which we introduced in 2008 and which form
an axiomatizable class. Furthermore we give necessary and sufficient conditions
for a definably complete Baire expansion of an o-minimal structure by C-infinity
functions to be o-minimal
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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