for Journals by Title or ISSN for Articles by Keywords help
 Subjects -> MATHEMATICS (Total: 909 journals)     - APPLIED MATHEMATICS (75 journals)    - GEOMETRY AND TOPOLOGY (20 journals)    - MATHEMATICS (676 journals)    - MATHEMATICS (GENERAL) (41 journals)    - NUMERICAL ANALYSIS (19 journals)    - PROBABILITIES AND MATH STATISTICS (78 journals) MATHEMATICS (676 journals)                  1 2 3 4 | Last

1 2 3 4 | Last

 Annali di Matematica Pura ed Applicata   [SJR: 1.167]   [H-I: 26]   [1 followers]  Follow         Hybrid journal (It can contain Open Access articles)    ISSN (Print) 1618-1891 - ISSN (Online) 0373-3114    Published by Springer-Verlag  [2355 journals]
• The infinitesimally bendable Euclidean hypersurfaces
• Authors: M. Dajczer; Th. Vlachos
Pages: 1961 - 1979
Abstract: Abstract The main purpose of this paper is to complete the work initiated by Sbrana in 1909 giving a complete local classification of the nonflat infinitesimally bendable hypersurfaces in Euclidean space.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0641-8
Issue No: Vol. 196, No. 6 (2017)

• A subset of Caffarelli–Kohn–Nirenberg inequalities in the hyperbolic
space $${{\mathbb {H}}}^N$$ H N
• Authors: Kunnath Sandeep; Cyril Tintarev
Pages: 2005 - 2021
Abstract: Abstract We prove a subset of inequalities of Caffarelli–Kohn–Nirenberg type in the hyperbolic space $${{\mathbb {H}}^N}, N\ge 2$$ , based on invariance with respect to a certain nonlinear scaling group, and study existence of corresponding minimizers. Earlier results concerning the Moser–Trudinger inequality are now interpreted in terms of CKN inequalities on the Poincaré disk.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0650-7
Issue No: Vol. 196, No. 6 (2017)

• Multiple standing waves for the nonlinear Helmholtz equation concentrating
in the high frequency limit
• Authors: Gilles Evéquoz
Pages: 2023 - 2042
Abstract: Abstract This paper studies for large frequency number $$k>0$$ the existence and multiplicity of solutions of the semilinear problem \begin{aligned} -\varDelta u -k^2 u=Q(x) u ^{p-2}u\quad \text { in }\mathbb {R}^N, \quad N\ge 2. \end{aligned} The exponent p is subcritical, and the coefficient Q is continuous, nonnegative and satisfies the condition \begin{aligned} \limsup _{ x \rightarrow \infty }Q(x)<\sup _{x\in \mathbb {R}^N}Q(x). \end{aligned} In the limit $$k\rightarrow \infty$$ , sequences of solutions associated with ground states of a dual equation are shown to concentrate, after rescaling, at global maximum points of the function Q.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0651-6
Issue No: Vol. 196, No. 6 (2017)

• Multiplicity of positive solutions for a class of fractional Schrödinger
equations via penalization method
• Authors: Vincenzo Ambrosio
Pages: 2043 - 2062
Abstract: Abstract By using the penalization method and the Ljusternik–Schnirelmann theory, we investigate the multiplicity of positive solutions of the following fractional Schrödinger equation \begin{aligned} \varepsilon ^{2s}(-\Delta )^{s} u + V(x)u = f(u)\quad \text{ in } {\mathbb {R}}^{N} \end{aligned} where $$\varepsilon >0$$ is a parameter, $$s\in (0, 1)$$ , $$N>2s$$ , $$(-\Delta )^{s}$$ is the fractional Laplacian, V is a positive continuous potential with local minimum, and f is a superlinear function with subcritical growth. We also obtain a multiplicity result when $$f(u)= u ^{q-2}u+\lambda u ^{r-2}u$$ with $$2<q<2^{*}_{s}\le r$$ and $$\lambda >0$$ , by combining a truncation argument and a Moser-type iteration.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0652-5
Issue No: Vol. 196, No. 6 (2017)

• Conformal minimal surfaces immersed into $${\mathbb {H}}P^{n}$$ H P n
• Authors: Xiaodong Chen; Xiaoxiang Jiao
Pages: 2063 - 2076
Abstract: Abstract In this paper, we want to construct conformal minimal surfaces and conformal minimal two-spheres in $${\mathbb {H}}P^{n}$$ by the twistor map $$\pi : {\mathbb {C}}P^{2n+1} \rightarrow {\mathbb {H}}P^{n}$$ . The construction is due to Eells and Wood’s conclusion about the composition of a horizontal harmonic map in 1983. Firstly, we give a characterization of horizontal holomorphic surfaces in $${\mathbb {C}}P^{5}$$ . Under this characterization, we construct eight families of conformal minimal surfaces in $${\mathbb {H}}P^{2}$$ . Then, we study horizontal Veronese sequences in $${\mathbb {C}}P^{4}$$ and $${\mathbb {C}}P^{5}$$ , and we transform the construction into solving a quadratic equation. Based on this, we get some examples of conformal minimal two-spheres in $${\mathbb {H}}P^{2}$$ with constant curvature $$\frac{4}{5}$$ and $$\frac{4}{13}$$ .
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0653-4
Issue No: Vol. 196, No. 6 (2017)

• On the cone of strong Kähler with torsion metrics
• Authors: Michele Maschio
Pages: 2077 - 2089
Abstract: Abstract This paper examines special metrics on compact complex manifolds, and it is notably focused on the notion of super strong Kähler with torsion metric. This condition is related to the strong Kähler with torsion one in the same manner as the strongly Gauduchon condition is related to the Gauduchon one. Moreover, we provide sufficient and necessary conditions so that every strong Kähler with torsion metric on a compact complex manifold is in fact super strong Kähler with torsion. We prove that these conditions are verified on compact complex manifolds satisfying $$\partial \overline{\partial }$$ -lemma but not on 6-dimensional compact complex nilmanifolds.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0654-3
Issue No: Vol. 196, No. 6 (2017)

• A regularity class for the roots of nonnegative functions
• Authors: Kolyan Ray; Johannes Schmidt-Hieber
Pages: 2091 - 2103
Abstract: Abstract We investigate the regularity of the positive roots of a nonnegative function of one-variable. A modified Hölder space $$\mathcal {F}^\beta$$ is introduced such that if $$f\in \mathcal {F}^\beta$$ then $$f^\alpha \in C^{\alpha \beta }$$ . This provides sufficient conditions to overcome the usual limitation in the square root case ( $$\alpha = 1/2$$ ) for Hölder functions that $$f^{1/2}$$ need be no more than $$C^1$$ in general. We also derive bounds on the wavelet coefficients of $$f^\alpha$$ , which provide a finer understanding of its local regularity.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0655-2
Issue No: Vol. 196, No. 6 (2017)

• Existence of martingale solutions and the incompressible limit for
stochastic compressible flows on the whole space
• Authors: Prince Romeo Mensah
Pages: 2105 - 2133
Abstract: Abstract We give an existence and asymptotic result for the so-called finite energy weak martingale solution of the compressible isentropic Navier–Stokes system driven by some random force in the whole spatial region. In particular, given a general nonlinear multiplicative noise, we establish the convergence to the incompressible system as the Mach number, representing the ratio between the average flow velocity and the speed of sound, approaches zero.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0656-1
Issue No: Vol. 196, No. 6 (2017)

• Characterizing spheres and Euclidean spaces by conformal vector fields
• Authors: Sharief Deshmukh
Pages: 2135 - 2145
Abstract: Abstract It is well known that the Euclidean space $$(R^{n},\left\langle ,\right\rangle )$$ , the n-sphere $$S^{n}(c)$$ of constant curvature c are examples of spaces admitting many conformal vector fields, and therefore conformal vector fields are used in obtaining characterizations of these spaces. In this paper, we use nontrivial conformal vector fields on a compact and connected Riemannian manifold to characterize the sphere $$S^{n}(c)$$ . Also, we use a nontrivial conformal vector field on a complete and connected Riemannian manifold and find characterizations for a Euclidean space $$(R^{n},\left\langle ,\right\rangle )$$ and the sphere $$S^{n}(c)$$ .
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0657-0
Issue No: Vol. 196, No. 6 (2017)

• Partial regularity results for non-autonomous functionals with $$\varPhi$$ Φ -growth conditions
• Authors: Flavia Giannetti; Antonia Passarelli di Napoli; Atsushi Tachikawa
Pages: 2147 - 2165
Abstract: Abstract We prove the partial Hölder continuity of the local minimizers of non-autonomous integral functionals of the type \begin{aligned} \int _\varOmega \varPhi \left( \big ( A^{\alpha \beta }_{ij}(x,u) D_iu^\alpha D_ju^\beta \big )^{1/2}\right) \mathrm{d}x, \end{aligned} where $$\varPhi$$ is an Orlicz function satisfying both the $$\varDelta _2$$ and $$\nabla _2$$ conditions and the function $$A(x,s) = \big (A^{\alpha \beta }_{ij}(x,s)\big )$$ is uniformly elliptic, bounded and continuous. Assuming in addition that the function $$A(x,s) = \big (A^{\alpha \beta }_{ij}(x,s)\big )$$ is Hölder continuous, we prove the partial Hölder continuity also of the gradient of the local minimizers.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0658-z
Issue No: Vol. 196, No. 6 (2017)

• On a conjecture of De Giorgi related to homogenization
• Authors: Aram L. Karakhanyan; Henrik Shahgholian
Pages: 2167 - 2183
Abstract: Abstract For a periodic vector field F, let $$X^\varepsilon$$ solve the dynamical system \begin{aligned} \frac{{\hbox {d}}{\hbox {X}}^{\varepsilon }}{{\hbox {d}}t} = {{F}}\left( \frac{{X}^{\varepsilon }}{\varepsilon }\right) . \end{aligned} In (Set Valued Anal 2(1–2):175–182, 1994) Ennio De Giorgi enquiers whether from the existence of the limit $$X^0(t):=\lim \nolimits _{\varepsilon \rightarrow 0} X^\varepsilon (t)$$ one can conclude that $$\frac{{\hbox {d}} X^0}{{\hbox {d}}t}= {\hbox {constant}}$$ . Our main result settles this conjecture under fairly general assumptions on F, which in some cases may also depend on t-variable. Once the above problem is solved, one can apply the result to the corresponding transport equation, in a standard way. This is also touched upon in the text to follow.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0659-y
Issue No: Vol. 196, No. 6 (2017)

• Classification of homogeneous minimal immersions from $$S^2$$ S 2 to
$${\mathbb {H}}P^n$$ H P n
• Authors: Jie Fei; Ling He
Pages: 2213 - 2237
Abstract: Abstract In this paper we determine all homogeneous minimal immersions of 2-spheres in quaternionic projective spaces $${\mathbb {H}}P^n$$ .
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0661-4
Issue No: Vol. 196, No. 6 (2017)

• Convolvability and regularization of distributions
• Authors: C. Bargetz; E. A. Nigsch; N. Ortner
Pages: 2239 - 2251
Abstract: Abstract We apply L. Schwartz’ theory of vector-valued distributions in order to simplify, unify and generalize statements about convolvability of distributions, their regularization properties and topological properties of sets of distributions. The proofs rely on propositions on the multiplication of vector-valued distributions and on the characterization of the spaces $$\mathcal {O}_{M}(E,F)$$ and $$\mathcal {O}_{C}'(E,F)$$ of multipliers and convolutors for distribution spaces E and F.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0662-3
Issue No: Vol. 196, No. 6 (2017)

• Two-dimensionality of gravity water flows governed by the equatorial f
-plane approximation
• Authors: Calin Iulian Martin
Pages: 2253 - 2260
Abstract: Abstract We show that gravity wave trains governed by the equatorial f-plane approximation propagate at the free surface of a rotational water flow of constant vorticity vector $$(\Omega _1, \Omega _2, \Omega _3)$$ over a flat bed only if the flow is two-dimensional. Owing to the presence of Coriolis effects, our result is also true even if the vorticity vector vanishes. This represents a striking difference when compared with the cases without geophysical effects discussed in Constantin (Europhys Lett 86:29001, 2009, Eur J Mech 30:12–16; 2011) and Martin (J Math Fluid Mech 2016. doi:10.1007/s00021-016-0306-1), where the conclusion about the two-dimensionality of the flow was possible under the assumption of constant nonvanishing vorticity vector. Another upshot is that the only nonzero component of the vorticity that may not vanish is $$\Omega _2$$ , that is, the one pointing in the horizontal direction orthogonal to the direction of wave propagation.
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0663-2
Issue No: Vol. 196, No. 6 (2017)

• Density of bounded maps in Sobolev spaces into complete manifolds
• Authors: Pierre Bousquet; Augusto C. Ponce; Jean Van Schaftingen
Pages: 2261 - 2301
Abstract: Abstract Given a complete noncompact Riemannian manifold $$N^n$$ , we investigate whether the set of bounded Sobolev maps $$(W^{1, p} \cap L^\infty ) (Q^m; N^n)$$ on the cube $$Q^{m}$$ is strongly dense in the Sobolev space $$W^{1, p} (Q^m; N^n)$$ for $$1 \le p \le m$$ . The density always holds when p is not an integer. When p is an integer, the density can fail, and we prove that a quantitative trimming property is equivalent with the density. This new condition is ensured, for example, by a uniform Lipschitz geometry of $$N^{n}$$ . As a by-product, we give necessary and sufficient conditions for the strong density of the set of smooth maps $$C^\infty (\overline{Q^m}; N^n)$$ in $$W^{1, p} (Q^m; N^n)$$ .
PubDate: 2017-12-01
DOI: 10.1007/s10231-017-0664-1
Issue No: Vol. 196, No. 6 (2017)

• Sign-changing bubble tower solutions for the supercritical Hénon-type
equations
• Authors: Daomin Cao; Zhongyuan Liu; Shuangjie Peng
Abstract: Abstract This paper deals with the following supercritical Hénon-type equation \begin{aligned} {\left\{ \begin{array}{ll} -\Delta u= x ^\alpha u ^{p_\alpha -1-\varepsilon }u~~&{}\text {in}~\Omega ,\\ u=0~~&{}\text {on}~\partial \Omega , \end{array}\right. } \end{aligned} where $$\alpha >-2$$ , $$\varepsilon >0$$ , $$p_\alpha =\frac{N+2+2\alpha }{N-2}$$ , $$N\ge 3$$ , $$\Omega$$ is a smooth bounded domain in $$\mathbb {R}^N$$ containing the origin. For $$\varepsilon >0$$ small enough, it is shown that if $$\alpha$$ is not an even integer, the above problem has sign-changing bubble tower solutions, which blow up at the origin. It seems that this is the first existence result of sign-changing bubble tower solutions for the supercritical Hénon-type equation.
PubDate: 2017-12-27
DOI: 10.1007/s10231-017-0722-8

• Counterexamples to the local–global divisibility over elliptic
curves
• Authors: Gabriele Ranieri
Abstract: Abstract Let $$p \ge 5$$ be a prime number. We find all the possible subgroups G of $$\mathrm{GL}_2 ({\mathbb Z}/ p {\mathbb Z})$$ such that there exist a number field k and an elliptic curve $${\mathcal {E}}$$ defined over k such that the $$\mathrm{Gal}(k ({\mathcal {E}}[p])/k)$$ -module $${\mathcal {E}}[p]$$ is isomorphic to the G-module $$({\mathbb Z}/ p {\mathbb Z})^2$$ and there exists $$n \in {\mathbb N}$$ such that the local–global divisibility by $$p^n$$ does not hold over $${\mathcal {E}}(k)$$ .
PubDate: 2017-12-12
DOI: 10.1007/s10231-017-0721-9

• Analytic and Gevrey hypoellipticity for perturbed sums of squares
operators
• Authors: Antonio Bove; Gregorio Chinni
Abstract: Abstract We prove a couple of results concerning pseudodifferential perturbations of differential operators being sums of squares of vector fields and satisfying Hörmander’s condition. The first is on the minimal Gevrey regularity: if a sum of squares with analytic coefficients is perturbed with a pseudodifferential operator of order strictly less than its subelliptic index it still has the Gevrey minimal regularity. We also prove a statement concerning real analytic hypoellipticity for the same type of pseudodifferential perturbations, provided the operator satisfies to some extra conditions (see Theorem 1.2 below) that ensure the analytic hypoellipticity.
PubDate: 2017-12-11
DOI: 10.1007/s10231-017-0720-x

• Parabolic conformally symplectic structures II: parabolic contactification
• Authors: Andreas Čap; Tomáš Salač
Abstract: Abstract Parabolic almost conformally symplectic structures were introduced in the first part of this series of articles as a class of geometric structures which have an underlying almost conformally symplectic structure. If this underlying structure is conformally symplectic, then one obtains a PCS-structure. In the current article, we relate PCS-structures to parabolic contact structures. Starting from a parabolic contact structure with a transversal infinitesimal automorphism, we first construct a natural PCS-structure on any local leaf space of the corresponding foliation. Then we develop a parabolic version of contactification to show that any PCS-structure can be locally realized (uniquely up to isomorphism) in this way. In the second part of the paper, these results are extended to an analogous correspondence between contact projective structures and so-called conformally Fedosov structures. The developments in this article provide the technical background for a construction of sequences and complexes of differential operators which are naturally associated to PCS-structures by pushing down BGG sequences on parabolic contact structures. This is the topic of the third part of this series of articles.
PubDate: 2017-12-05
DOI: 10.1007/s10231-017-0719-3

• Correction to: The infinitesimally bendable Euclidean hypersurfaces
• Authors: M. Dajczer; Th. Vlachos
Abstract: Abstract All the results of the paper remain true as stated but there is a serious gap in the proof of Theorem 13. Equations (26) and (27) need to be corrected.
PubDate: 2017-10-13
DOI: 10.1007/s10231-017-0700-1

JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327

Home (Search)
Subjects A-Z
Publishers A-Z
Customise
APIs