منابع مشابه
Two Counterexamples in Low-dimensional Length Geometry
One of the key properties of the length of a curve is its lower semicontinuity : if a sequence of curves γi converges to a curve γ, then length(γ) ≤ lim inf length(γi). Here the weakest type of pointwise convergence suffices. There are higher-dimensional analogs of this semicontinuity for Riemannian (and even Finsler) metrics. For instance, the Besicovitch inequality (see, e.g., [1] and [4]) im...
متن کاملTwo counterexamples on completely independent spanning trees
For each k ≥ 2, we construct a k-connected graph which does not contain two completely independent spanning trees. This disproves a conjecture of Hasunuma. Furthermore, we also give an example for a 3-connected maximal plane graph not containing two completely independent spanning trees.
متن کاملCOUNTEREXAMPLES IN CHAOTIC GENERALIZED SHIFTS
In the following text for arbitrary $X$ with at least two elements, nonempty countable set $Gamma$ we make a comparative study on the collection of generalized shift dynamical systems like $(X^Gamma,sigma_varphi)$ where $varphi:GammatoGamma$ is an arbitrary self-map. We pay attention to sub-systems and combinations of generalized shifts with counterexamples regarding Devaney, exact Dev...
متن کاملTwo Counterexamples in the Logic of Dynamic Topological Systems
The classical Tarski theorem on topological semantics of modal logic states that the logic S4 is complete in R for each n. Recently several authors have considered logics of dynamic topological systems, which is a topological space and a function on it. In [1] a bimodal logic S4C was introduced and proven to be complete with respect to the class of all continuous dynamic systems. A number of po...
متن کاملTwo Counterexamples in the Theory of Singular Integrals
In these lectures we discuss examples that are relevant to two questions in the theory of singular integrals. The first question is the L boundedness of the maximal operator formed by dilates of Mikhlin-Hörmander multipliers, while the second concerns the L boundedness of a well-known object, the classical L-bounded Calderón-Zygmund homogeneous singular integral associated with an integrable fu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Proceedings of the American Mathematical Society
سال: 2007
ISSN: 0002-9939
DOI: 10.1090/s0002-9939-07-09010-7