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Non-uniformly local tent spaces
http://ddd.uab.cat/record/128228
We develop a theory of `non-uniformly local' tent spaces on metric mea- sure spaces. As our main result, we give a remarkably simple proof of the atomic decomposition. Amenta, AlexMon, 19 Jan 2015 18:38:06 GMThttp://ddd.uab.cat/record/128228New invariants and attracting domains for holomorphic maps in C2 tangent to the identity
http://ddd.uab.cat/record/128227
We study holomorphic maps of C2 tangent to the identity at fixed point which have degenerate characteristic directions. With the help of some new invariants, we give suficient conditions for the existence of attracting domains in these degenerate characteristic directions. Rong, FengMon, 19 Jan 2015 18:35:40 GMThttp://ddd.uab.cat/record/128227On determinant functors and -theory
http://ddd.uab.cat/record/128226
We extend Deligne's notion of determinant functor to Waldhausen categories and (strongly) triangulated categories. We construct explicit universal determinant functors in each case, whose target is an algebraic model for the 1-type of the corresponding K-theory spectrum. As applications, we answer open questions by Maltsiniotis and Neeman on the K-theory of (strongly) triangulated categories and a question of Grothendieck to Knudsen on determinant functors. We also prove additivity theorems for low-dimensional K-theory of (strongly) triangulated categories and obtain generators and (some) relations for various K1-groups. This is achieved via a unfied theory of determinant functors which can be applied in further contexts, such as derivators. Muro, FernandoMon, 19 Jan 2015 18:32:46 GMThttp://ddd.uab.cat/record/128226Fraction-like ratings from preferential voting
http://ddd.uab.cat/record/128225
A method is given for resolving a matrix of preference scores into a well-specfied mixture of options. This is done in agreement with several desirable properties, including the continuity of the mixing proportions with respect to the preference scores and a condition of compatibility with the Condorcet-Smith majority principle. These properties are achieved by combining the classical rating method of Zermelo with a projection procedure introduced in previous papers of the same authors. Camps, R.Mon, 19 Jan 2015 18:28:25 GMThttp://ddd.uab.cat/record/128225Elimination of resonances in codimension one foliations
http://ddd.uab.cat/record/128224
The problem of reduction of singularities for germs of codimension one foliations in dimension three has been solved by Cano in [3]. The author divides the proof in two steps. The first one consists in getting pre-simple points and the second one is the passage from pre-simple to simple points. In arbitrary dimension of the ambient space the problem is open. In this paper we solve the second step of the problem. Fernández Duque, M.Mon, 19 Jan 2015 18:24:45 GMThttp://ddd.uab.cat/record/128224Dense infinite Bh sequences
http://ddd.uab.cat/record/128223
Cilleruelo, J.Mon, 19 Jan 2015 18:16:20 GMThttp://ddd.uab.cat/record/128223Blaschke products and Nevanlinna-Pick interpolation
http://ddd.uab.cat/record/128222
For a Nevanlinna{Pick problem with more than one solution, Rolf Nevanlinna proved that all extremal solutions are inner functions. If the interpolation points are contained in dinitely many cones terminating at the unit circle, it is shown that all extremal solutions are Blaschke products. Stray, A.Mon, 19 Jan 2015 18:14:17 GMThttp://ddd.uab.cat/record/128222Logarithmic bump conditions for Calderón-Zygmund operators on spaces of homogeneous type
http://ddd.uab.cat/record/128221
We establish two-weight norm inequalities for singular integral operators defined on spaces of homogeneous type. We do so first when the weights satisfy a double bump condition and then when the weights satisfy separated logarithmic bump conditions. Our results generalize recent work on the Euclidean case, but our proofs are simpler even in this setting. The other interesting feature of our approach is that we are able to prove the separated bump results (which always imply the corresponding double bump results) as a consequence of the double bump theorem. Anderson, T. C.Mon, 19 Jan 2015 18:11:21 GMThttp://ddd.uab.cat/record/128221Conjugacy in Houghton's groups
http://ddd.uab.cat/record/128220
Antolín, Y.Mon, 19 Jan 2015 18:06:10 GMThttp://ddd.uab.cat/record/128220Memorial for our Editorial Board Member Marc Yor
http://ddd.uab.cat/record/119048
Revista Publicacions matemàtiquesThu, 10 Jul 2014 11:55:06 GMThttp://ddd.uab.cat/record/119048The Riesz transform, rectifiability, and removability for Lipschitz harmonic functions
http://ddd.uab.cat/record/119046
We show that, given a set E Rn+1 with finite n-Hausdorff measure Hn, if the n-dimensional Riesz transform is bounded in L2(HnbE), then E is n-rectifiable. From this result we deduce that a compact set E Rn+1 with Hn(E) < 1 is removable for Lipschitz harmonic functions if and only if it is purely n-unrectifiable, thus proving the analog of Vitushkin's conjecture in higher dimensions. Nazarov, FedorThu, 10 Jul 2014 11:51:28 GMThttp://ddd.uab.cat/record/119046Embeddings of local fields in simple algebras and simplicial structures
http://ddd.uab.cat/record/119044
We give a geometric interpretation of Broussous{Grabitz embedding types. We fix a central division algebra D of finite index over a non-Archimedean local field F and a positive integer m. Further we fix a hereditary order a of Mm(D) and an unramified field extension EjF in Mm(D) which is embeddable in D and which normalizes a. Such a pair (E, a) is called an embedding. The embedding types classify the GLm(D)-conjugation classes of these embeddings. Such a type is a class of matrices with non-negative integer entries. We give a formula which allows us to recover the embedding type of (E, a) from the simplicial type of the image of the barycenter of a under the canonical isomorphism, from the set of Ex-fixed points of the reduced building of GLm(D) to the reduced building of the centralizer of Ex in GLm(D). Conversely the formula allows to calculate the simplicial type up to cyclic permutation of the Coxeter diagram. Skodlerack, DanielThu, 10 Jul 2014 11:32:28 GMThttp://ddd.uab.cat/record/119044Comparison principle and constrained radial symmetry for the subdiffusive p-laplacian
http://ddd.uab.cat/record/119042
A comparison principle for the subdiffusive p-Laplacian in a possibly non-smooth and unbounded open set is proved. The result requires that the involved suband supersolution are positive, and the ratio of the former to the latter is bounded. As an application, constrained radial symmetry for overdetermined problems is obtained. More precisely, both Dirichlet and Neumann conditions are prescribed on the boundary of a bounded open set, and the Neumann condition depends on the distance from the origin. The domain of the problem, unknown at the beginning, turns out to be a ball centered at the origin if a positive solution exists. Counterexamples are also discussed. Greco, AntonioThu, 10 Jul 2014 11:16:17 GMThttp://ddd.uab.cat/record/119042Third-power associative absolute valued algebras with a nonzero idempotent commuting with all idempotents
http://ddd.uab.cat/record/119040
This paper deals with the determination of the absolute valued algebras with a nonzero idempotent commuting with the remaining idempotents and satisfying x2x = xx2 for every x. We prove that, in addition to the absolute valued algebras R, C, H, or O of the reals, complexes, division real quaternions or division real octonions, one such absolute valued algebra A can also be isometrically isomorphic to some of the absolute valued algebras C. H or O, obtained from C, H, and O by imposing a new product defined by multiplying the conjugates of the elements. In particular, every absolute valued algebra having the above properties is finite-dimensional. This generalizes some well known theorems of Albert, Urbanik and Wright, and El-Mallah. Cuenca Mira, José AntonioThu, 10 Jul 2014 11:05:23 GMThttp://ddd.uab.cat/record/119040Explicit minimal scherk saddle towers of arbitrary even genera in R3
http://ddd.uab.cat/record/119039
Starting from works by Scherk (1835) and by Enneper-Weierstrass (1863), new minimal surfaces with Scherk ends were found only in 1988 by Karcher (see [9, 10]). In the singly periodic case, Karcher's examples of positive genera had been unique until Traizet obtained new ones in 1996 (see [23]). However, Traizet's construction is implicit and excludes towers, namely the desingularisation of more than two concurrent planes. Then, new explicit towers were found only in 2006 by Martín and Ramos Batista (see [13]), all of them with genus one. For genus two, the first such towers were constructed in 2010 (see [22]). Back to 2009, implicit towers of arbitrary genera were found in [5]. In our present work we obtain explicit minimal Scherk saddle towers, for any given genus 2k, k 3. Yucra Hancco, A. J.Thu, 10 Jul 2014 09:58:13 GMThttp://ddd.uab.cat/record/119039On restricted weak-type constants of Fourier multipliers
http://ddd.uab.cat/record/119038
We exhibit a large class of symbols m: Rd ! C for which the corresponding Fourier multipliers Tm satisfy the following restricted weak-type estimates: if A Rd has finite Lebesgue measure, then. . . In particular, this leads to novel sharp estimates for the real and imaginary part of the Beurling-Ahlfors operator on C. The proof rests on probabilistic methods: we exploit a stochastic representation of the multipliers in terms of Lévy processes and appropriate sharp inequalities for differentially subordinated martingales. Osekowski, AdamThu, 10 Jul 2014 09:46:01 GMThttp://ddd.uab.cat/record/119038On separated Carleson sequences in the unit disc
http://ddd.uab.cat/record/119034
The interpolating sequences S for H∞(D), the bounded holomorphic functions in the unit disc D of the complex plane C, were characterized by L. Carleson using metric conditions on S. Alternatively, to characterize interpolating sequences we can use the existence in H∞(D) of an inﬁnity of functions {ρa}a∈S, uniformly bounded in D, the function ρa being 1 at the point a ∈ S and 0 at any b ∈ S \ {a}. A. Hartmann recently proved that just one function in H∞(D) was enough to characterize interpolating sequences for H∞(D). In this work we use the “hard” part of Carleson’s proof of the corona theorem to extend Hartmann’s result and to answer a question he asked in his paper. Amar, EricWed, 09 Jul 2014 11:45:02 GMThttp://ddd.uab.cat/record/119034Smoothing properties of the discrete fractional maximal operator on Besov and Triebel-Lizorkin spaces
http://ddd.uab.cat/record/119033
Motivated by the results of Korry, and Kinnunen and Saksman, we study the behaviour of the discrete fractional maximal operator on fractional Hajlasz spaces, Hajlasz-Besov, and Hajlasz-Triebel-Lizorkin spaces on metric measure spaces. We show that the discrete fractional maximal operator maps these spaces to the spaces of the same type with higher smoothness. Our results extend and unify aforementioned results. We present our results in a general setting, but they are new already in the Euclidean case. Heikkinen, ToniWed, 09 Jul 2014 11:33:42 GMThttp://ddd.uab.cat/record/119033Atomic decomposition of real-variable type for Bergman spaces in the unit ball of Cn
http://ddd.uab.cat/record/119032
In this paper we show that, for any 0 < p _ 1 and _ > 1, every (weighted) Bergman space Ap _(Bn) admits an atomic decomposition of real-variable type. More precisely, for each f 2 Ap _(Bn) there exist a sequence of (p;1)_-atoms ak with compact support and a scalar sequence f_kg such that f = P k _kak in the sense of distribution and Pk j_kjp . kfkp p and moreover, f = Pk _kP_(ak) in Ap_(Bn); where P_ is the orthogonal projection from L2_(Bn) onto A2_(Bn): The proof is constructive and our construction is based on analysis inside the unit ball Bn associated with a quasimetric. Chen, ZeqianWed, 09 Jul 2014 11:22:57 GMThttp://ddd.uab.cat/record/119032Stable sampling and fourier multipliers
http://ddd.uab.cat/record/119031
We study the relationship between stable sampling sequences for band-limited functions in Lp(Rn) and the Fourier multipliers in Lp. In the case that the sequence is a lattice and the spectrum is a fundamental domain for the lattice the connection is complete. In the case of irregular sequences there is still a partial relationship. Matei, BasarabWed, 09 Jul 2014 11:12:59 GMThttp://ddd.uab.cat/record/119031Groups with normality conditions for subgroups of infinite rank
http://ddd.uab.cat/record/119030
A well-known theorem of B. H. Neumann states that a group has finite conjugacy classes of subgroups if and only if it is central-by-finite. It is proved here that if G is a generalized radical group of infinite rank in which the conjugacy classes of subgroups of infinite rank are finite, then every subgroup of G has finitely many conjugates, and so G=Z(G) is finite. Corresponding results are proved for groups in which every subgroup of infinite rank has fiznite index in its normal closure, and for those in which every subgroup of infinite rank is finite over its core. De Falco, MariaWed, 09 Jul 2014 10:58:09 GMThttp://ddd.uab.cat/record/119030Resultant and conductor of geometrically semi-stable self maps of the projective line over a number field or function field
http://ddd.uab.cat/record/119029
We study the minimal resultant divisor of self-maps of the projective line over a number field or a function field and its relation to the conductor. The guiding focus is the exploration of a dynamical analog to Theorem 1. 1, which bounds the degree of the minimal discriminant of an elliptic surface in terms of the conductor. The main theorems of this paper (5. 5 and 5. 6) establish that, for a degree 2 map, semi-stability in the Geometric Invariant Theory sense on the space of self maps, implies minimality of the resultant. We prove the singular reduction of a semi-stable presentation coincides with the simple bad reduction (Theorem 4. 1). Given an elliptic curve over a function field with semi-stable bad reduction, we show the associated Lattès map has unstable bad reduction Proposition 4. 6). Degree 2 maps in normal form with semi-stable bad reduction are used to construct a counterexample (Example 3. 1) to a simple dynamical analog to Theorem 1. 1. Szpiro, LucienWed, 09 Jul 2014 10:17:17 GMThttp://ddd.uab.cat/record/119029A PDE approach of inflammatory phase dynamics in diabetic wounds
http://ddd.uab.cat/record/119028
The objective of the present paper is the modeling and analysis of the dynamics of macrophages and certain growth factors in the inﬂammatory phase, the ﬁrst one of the wound healing process. It is the phase where there exists a major difference between diabetic and non-diabetic wound healing, an effect that we will consider in this paper. Cónsul, N.Wed, 09 Jul 2014 09:35:13 GMThttp://ddd.uab.cat/record/119028Bautin ideals and Taylor domination
http://ddd.uab.cat/record/118324
Yomdin, Y.Mon, 19 May 2014 17:50:50 GMThttp://ddd.uab.cat/record/118324Uniform methods to stablish Poincaré type linearization theorems
http://ddd.uab.cat/record/118322
We find a uniform method to establish Poincaré type linearization theorems for regular systems including classical autonomous, random and almost periodic ones via modified majorant norm methods. Wu, HaoMon, 19 May 2014 16:35:01 GMThttp://ddd.uab.cat/record/118322