A product integral representation of the generalized inverse
A proof of admissibility of a class of random normed spaces
A proof of Nehari's theorem through the coefficient of a matricial measure.
A proof of the Grünbaum conjecture
Let V be an n-dimensional real Banach space and let λ(V) denote its absolute projection constant. For any N ∈ N with N ≥ n define , λₙ = supλ(V): dim(V) = n. A well-known Grünbaum conjecture [Trans. Amer. Math. Soc. 95 (1960)] says that λ₂ = 4/3. König and Tomczak-Jaegermann [J. Funct. Anal. 119 (1994)] made an attempt to prove this conjecture. Unfortunately, their Proposition 3.1, used in the proof, is incorrect. In this paper a complete proof of the Grünbaum conjecture is presented
A proof of the inverse function theorem
A proof of the Markov-Kakutani fixed point theorem via the Hahn-Banach theorem.
A proof of the Schauder-Tychonoff theorem.
-properness and fixed point theorems for dissipative type maps.
A property of semigroups on metric spaces.
À propos de quelque opérateurs non linéaries.
A q-analogue of complete monotonicity
The aim of this paper is to give a q-analogue for complete monotonicity. We apply a classical characterization of Hausdorff moment sequences in terms of positive definiteness and complete monotonicity, adapted to the q-situation. The method due to Maserick and Szafraniec that does not need moments turns out to be useful. A definition of a q-moment sequence appears as a by-product.
A quantified Tauberian theorem for sequences
The main result of this paper is a quantified version of Ingham's Tauberian theorem for bounded vector-valued sequences rather than functions. It gives an estimate on the rate of decay of such a sequence in terms of the behaviour of a certain boundary function, with the quality of the estimate depending on the degree of smoothness this boundary function is assumed to possess. The result is then used to give a new proof of the quantified Katznelson-Tzafriri theorem recently obtained by the author...
A quantitative asymptotic theorem for contraction semigroups with countable unitary spectrum
Let T be a semigroup of linear contractions on a Banach space X, and let . Then is the annihilator of the bounded trajectories of T*. If the unitary spectrum of T is countable, then is the annihilator of the unitary eigenvectors of T*, and for each x in X.
A Quantitative Schauder Theorem.
A quasi-affine transform of an unbounded operator
Some results on quasi-affinity for bounded operators are extended to unbounded ones and normal extensions of an unbounded operator are discussed in connection with quasi-affinity.
A quasi-Newton method for solving fixed point problems in Hilbert spaces.
A quasinilpotent operator with reflexive commutant
An example of a nonzero quasinilpotent operator with reflexive commutant is presented.
A quasi-nilpotent operator with reflexive commutant, II
A new example of a non-zero quasi-nilpotent operator T with reflexive commutant is presented. The norms converge to zero arbitrarily fast.
A quasistatic bilateral contact problem with adhesion and friction for viscoelastic materials
We consider a mathematical model which describes a contact problem between a deformable body and a foundation. The contact is bilateral and is modelled with Tresca's friction law in which adhesion is taken into account. The evolution of the bonding field is described by a first order differential equation and the material's behavior is modelled with a nonlinear viscoelastic constitutive law. We derive a variational formulation of the mechanical problem and prove the existence and uniqueness result...
A quasistatic bilateral contact problem with friction for nonlinear elastic materials.