The upper bound on the value of the surface gravity, gs, for neutron stars with equations of state respecting vsound ≤ c, is derived. This bound is inversely proportional to the maximum allowable mass Mmax, and it reads gs ≤ 1.411× 10 15 (Mmax/M⊙) −1 cm s. It implies an absolute upper bound 7.4× 10 cm s if one uses the 2σ lower bound on the neutron mass measured recently in 4U1700-37, 1.9M⊙. A ...

We introduce the class of countably I-compact spaces as a proper subclass of countably S-closed spaces. A topological space (X,T) is called countably I-compact if every countable cover of X by regular closed subsets contains a finite subfamily whose interiors cover X. It is shown that a space is countably I-compact if and only if it is extremally disconnected and countably S-closed. Other chara...

We study the Cauchy problem for 22 semilinear and quasilinear hyperbolic systems with a singular relaxation term. Special comparison and compactness properties are established by assuming the subcharacteristic condition. Therefore we can prove the convergence to equilibrium of the solutions of these problems as the singular perturbation parameter tends to zero. This research was strongly motiva...

We give a sequential compactness criterion for the weak topology of vector measures with values in certain nuclear spaces, such as the space S of all rapidly decreasing, infinitely differentiable functions, the space D of all test functions, and the strong duals of those spaces. This result contains Prokhorov–LeCam’s criterion for real measures and applies to cases which are not covered by März...

Let (R, μ) be a nonatomic finite measure space and E = Lr(R, μ) a Lebesgue space over R. Then we consider tempered distributions f and g (depending on x ∈ Rn and v ∈ R), for which divx(af) = g in S′(Rn, E). Here a : R −→ Rn is a bounded function of v (a velocity field) satisfying a nondegeneracy condition. We study the regularity of the average f̄ = R R f(·, v)ψ(v) dμ(v) ∈ S′(Rn) (with ψ ∈ Lr (R...

In this paper boundedness and compactness of generalized composition oper-ators from logarithmic Bloch type spaces to Q_K type spaces are investigated.

BACKGROUND AND AIMS Plant species typical of cold and warm habitats differ in a suite of morpho-physio-phenological traits, although their evolutionary routes have been poorly explored. Here, it is advocated that traits typical of different climate regimes can be largely driven by contrasting branch architectures. This is explored within Saxifraga. First, an investigation was carried out to det...

abstract: A base B of a space X is called an OIF base when every element of B is a subset of only a finite number of other elements of B. We will explore the fundamental properties of spaces having such bases. In particular, we will show that in T2 spaces, strong OIF bases are the same as uniform bases, and that in T3 spaces where all subspaces have OIF bases, compactness, countable compactness...

A base B of a space X is called an OIF base when every element of B is a subset of only a finite number of other elements of B. We will explore the fundamental properties of spaces having such bases. In particular, we will show that in T2 spaces, strong OIF bases are the same as uniform bases, and that in T3 spaces where all subspaces have OIF bases, compactness, countable compactness, or local...

In this paper, Lowen’s strong fuzzy compactness and ultra-fuzzy compactness of I -topological spaces are extended to L-subsets, for L—a complete lattice. The properties of strong fuzzy compact L-subsets and ultra-fuzzy compact L-subsets are studied in detail here, and comparisons between these notions as well as the notion of N-compactness are shown. c © 2004 Elsevier B.V. All rights reserved.