1,598 research outputs found
Kakeya sets over non-archimedean local rings
In a recent paper of Ellenberg, Oberlin, and Tao, the authors asked whether
there are Besicovitch phenomena in F_q[[t]]^n. In this paper, we answer their
question in the affirmative by explicitly constructing a Kakeya set in
F_q[[t]]^n of measure 0. Furthermore, we prove that any Kakeya set in
F_q[[t]]^2 or Z_p^2 is of Minkowski dimension 2.Comment: 10 page
Oribatid assemblies of tropical high mountains on some points of the “Gondwana-Bridge” – a case study
This work is the first part of a series of studies, which introduces the methodological possibilities of coenological and zoogeographical indication and – following the climate, vegetation and elevation zones – the pattern-describing analysis of the main Oribatid sinusia of the world explored till our days.This current work is a case-study, which displays the comparison of 9 examination sites from 3
different geographical locations. On each location, three vegetation types have been examined: a plain
rain-forest, a mossforest and a mountainous paramo. Analyses are based on the hitherto non-published
genus-level database and coenological tables of the deceased János Balogh professor. Occurrence of 18
genera is going to be published as new data for the given zoogeographical region
Explicit computations of Hida families via overconvergent modular symbols
In [Pollack-Stevens 2011], efficient algorithms are given to compute with
overconvergent modular symbols. These algorithms then allow for the fast
computation of -adic -functions and have further been applied to compute
rational points on elliptic curves (e.g. [Darmon-Pollack 2006, Trifkovi\'c
2006]). In this paper, we generalize these algorithms to the case of families
of overconvergent modular symbols. As a consequence, we can compute -adic
families of Hecke-eigenvalues, two-variable -adic -functions,
-invariants, as well as the shape and structure of ordinary Hida-Hecke
algebras.Comment: 51 pages. To appear in Research in Number Theory. This version has
added some comments and clarifications, a new example, and further
explanations of the previous example
Mechanisms of THz generation from silver nanoparticle and nanohole arrays illuminated by 100 fs pulses of infrared light
On Linear Codes with Random Multiplier Vectors and the Maximum Trace Dimension Property
Let be a linear code of length and dimension over the finite
field . The trace code is a linear code of
the same length over the subfield . The obvious upper bound
for the dimension of the trace code over is . If equality
holds, then we say that has maximum trace dimension. The problem of finding
the true dimension of trace codes and their duals is relevant for the size of
the public key of various code-based cryptographic protocols. Let
denote the code obtained from and a multiplier vector
. In this paper, we give a lower bound for
the probability that a random multiplier vector produces a code
of maximum trace dimension. We give an interpretation of the
bound for the class of algebraic geometry codes in terms of the degree of the
defining divisor. The bound explains the experimental fact that random
alternant codes have minimal dimension. Our bound holds whenever , where is the Singleton defect of . For the extremal case
, numerical experiments reveal a closed connection between the
probability of having maximum trace dimension and the probability that a random
matrix has full rank
Understanding Enemy Images in Central and Eastern European Politics. Towards an Interdisciplinary Approach
Europe has experienced a rise in politics based on antagonism, often discussed from the perspectives of populism and the mainstreaming of the ideologies of the radical right. In this study, we argue that there is a need for an interdisciplinary, theoretically broader and more empirically focused approach that fosters understanding of these developments. To explore the causal factors, we focus on the enemy images that are constructed and diffused by politicians, and their specific historical and structural contexts.V předchozích letech Evropa zažívá vzestup politiky založené na antagonismu, často diskutovaném v kontextu populismu a mainstreamingu ideologie radikální pravice. V tomto textu tvrdíme, že je třeba multidisciplinárního, teoreticky širšího a více empiricky zaměřeného přístupu pro porozumění tohoto vývoje. Pro zjištění kauzálních příčin se soustředíme na zobrazení nepřítele prezentované politiky a též na strukturální a specifické historické faktory
Multiscale Analysis of Spreading in a Large Communication Network
In temporal networks, both the topology of the underlying network and the
timings of interaction events can be crucial in determining how some dynamic
process mediated by the network unfolds. We have explored the limiting case of
the speed of spreading in the SI model, set up such that an event between an
infectious and susceptible individual always transmits the infection. The speed
of this process sets an upper bound for the speed of any dynamic process that
is mediated through the interaction events of the network. With the help of
temporal networks derived from large scale time-stamped data on mobile phone
calls, we extend earlier results that point out the slowing-down effects of
burstiness and temporal inhomogeneities. In such networks, links are not
permanently active, but dynamic processes are mediated by recurrent events
taking place on the links at specific points in time. We perform a multi-scale
analysis and pinpoint the importance of the timings of event sequences on
individual links, their correlations with neighboring sequences, and the
temporal pathways taken by the network-scale spreading process. This is
achieved by studying empirically and analytically different characteristic
relay times of links, relevant to the respective scales, and a set of temporal
reference models that allow for removing selected time-domain correlations one
by one
Variation for carbon isotope ratio in a set of emmer (Triticum dicoccum Schrank) and bread wheat (Triticum aestivum L.) accessions
A high level of drought tolerance is an important objective in breeding new generation wheat varieties. A group of six landraces of the emmer wheat (Triticum diccocum Schrank), as well as two landraces, two old cultivars and two modern varieties of bread wheat (Triticum aestivum L.) were evaluated for their ability to discriminate 13C, a trait related to stomatal closure and consequently, an important component tolerance to drought. Three emmer wheat landraces and one of the bread wheat landraces has the lowest. Therefore, emmer wheat may play the role of a donor of the tolerance to drought in wheat breeding programs targetting drought prone conditions.Key words: Emmer wheat, bread wheat, drought tolerance, carbon isotope ratio, discrimination
Circadian pattern and burstiness in mobile phone communication
The temporal communication patterns of human individuals are known to be
inhomogeneous or bursty, which is reflected as the heavy tail behavior in the
inter-event time distribution. As the cause of such bursty behavior two main
mechanisms have been suggested: a) Inhomogeneities due to the circadian and
weekly activity patterns and b) inhomogeneities rooted in human task execution
behavior. Here we investigate the roles of these mechanisms by developing and
then applying systematic de-seasoning methods to remove the circadian and
weekly patterns from the time-series of mobile phone communication events of
individuals. We find that the heavy tails in the inter-event time distributions
remain robustly with respect to this procedure, which clearly indicates that
the human task execution based mechanism is a possible cause for the remaining
burstiness in temporal mobile phone communication patterns.Comment: 17 pages, 12 figure
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