Search results for "Set theory"
showing 10 items of 751 documents
Rotationally symmetric p -harmonic maps fromD2toS2
2013
We consider rotationally symmetric p-harmonic maps from the unit disk D2⊂R2 to the unit sphere S2⊂R3, subject to Dirichlet boundary conditions and with 1<p<∞. We show that the associated energy functional admits a unique minimizer which is of class C∞ in the interior and C1 up to the boundary. We also show that there exist infinitely many global solutions to the associated Euler–Lagrange equation and we completely characterize them.
Exceptional Configurations of Quantum Walks with Grover’s Coin
2016
We study search by quantum walk on a two-dimensional grid using the algorithm of Ambainis, Kempe and Rivosh [AKR05]. We show what the most natural coin transformation -- Grover's diffusion transformation -- has a wide class of exceptional configurations of marked locations, for which the probability of finding any of the marked locations does not grow over time. This extends the class of known exceptional configurations; until now the only known such configuration was the "diagonal construction" by [AR08].
Nonlinear corrections to the DGLAP equations in view of the HERA data
2002
The effects of the first nonlinear corrections to the DGLAP evolution equations are studied by using the recent HERA data for the structure function $F_2(x,Q^2)$ of the free proton and the parton distributions from CTEQ5L and CTEQ6L as a baseline. By requiring a good fit to the H1 data, we determine initial parton distributions at $Q_0^2=1.4$ GeV$^2$ for the nonlinear scale evolution. We show that the nonlinear corrections improve the agreement with the $F_2(x,Q^2)$ data in the region of $x\sim 3\cdot 10^{-5}$ and $Q^2\sim 1.5$ GeV$^2$ without paying the price of obtaining a worse agreement at larger values of $x$ and $Q^2$. For the gluon distribution the nonlinear effects are found to play…
VIZUALINIS MOKTYTOJO ĮVAIZDIS: LYGINAMASIS TYRIMAS
2013
Dr. paed., Instituteof Educational Sciences, University of Latvia, Latvia. E-mail: iveta.kestere@lu.lv Address: Laimdotas 37, Rīga LV1006, Latvia Phone +371 29496660; +32 473 63 37 98PhD, Graduate School of Education, North West University, South Africa. E-mail: Charl.Wolhuter@nwu.ac.za Address: North-West University, Private Bag X 6001, Potchefstroom 2520, South AfricaPhD, Educational Sciences Department, Yeditepe University, Turkey. E-mail: ricardolozanov@gmail.comStraipsnyje „Vizualinis mokytojo įvaizdis: lyginamasis tyrimas“ pateikiami tyrimo, atlikto dešimtyje šalių – Anglijoje, Pietų Afrikoje, Serbijoje, Slovėnijoje, Graikijoje, Bulgarijoje, Latvijoje, Turkijoje, Pakistane ir Meksi…
The Village of the Year Competition Constructing an Ideal Model of a Rural Community in Finland
2016
The Village Action Association of Finland (SYTY) organizes the Village of the Year competition annually to award active rural communities. The competition has taken place since 1985, but after the village action movement was integrated into Finnish rural policy networks in the 1990s, it also became a part of rural policy instruments. The competition can be considered a governing technique that constructs norms and an ideal model for rural communities to pursue. In this article, I study the representation of an ideal rural community by analysing the criteria of the competition. I also look for changes to see whether the integration of the village action movement into rural policy is reflecte…
A Divergence-Free High-Resolution Code for MHD
2001
We describe a 2.5D numerical code to solve the equations of ideal magnetohydrodynamics (MHD). The numerical code, based on high-resolution shock-capturing (HRSC) techniques, solves the equations written in conservation form and computes the numerical fluxes using a linearized Riemann solver. A special procedure is used to force the conservation of magnetic flux along the time.
Enumerable classes of total recursive functions: Complexity of inductive inference
1994
This paper includes some results on complexity of inductive inference for enumerable classes of total recursive functions, where enumeration is considered in more general meaning than usual recursive enumeration. The complexity is measured as the worst-case mindchange (error) number for the first n functions of the given class. Three generalizations are considered.
A note on rank 2 diagonals
2020
<p>We solve two questions regarding spaces with a (G<sub>δ</sub>)-diagonal of rank 2. One is a question of Basile, Bella and Ridderbos about weakly Lindelöf spaces with a G<sub>δ</sub>-diagonal of rank 2 and the other is a question of Arhangel’skii and Bella asking whether every space with a diagonal of rank 2 and cellularity continuum has cardinality at most continuum.</p>
Free boundary methods and non-scattering phenomena
2021
We study a question arising in inverse scattering theory: given a penetrable obstacle, does there exist an incident wave that does not scatter? We show that every penetrable obstacle with real-analytic boundary admits such an incident wave. At zero frequency, we use quadrature domains to show that there are also obstacles with inward cusps having this property. In the converse direction, under a nonvanishing condition for the incident wave, we show that there is a dichotomy for boundary points of any penetrable obstacle having this property: either the boundary is regular, or the complement of the obstacle has to be very thin near the point. These facts are proved by invoking results from t…
A local approach to a class of locally finite groups
2003
This paper is devoted to the study of a class of generalised P-nilpotent groups in the universe cℒ̄ of all radical locally finite groups satisfying min-q for every prime q. Some results of finite groups are extended and a characterisation of the injectors associated with this class is given.