We extract verified algorithms for exact real number computation from constructive proofs. To this end we use a coinductive representation of reals as streams binary signed digits. The main objective paper is the formalisation proof that numbers are closed with respect to limits. All proofs theorem and first application implemented in Minlog system extracted terms further translated into Haskel...

It is proved that a Banach space contains a subspace isomorphic to l(1) if (and only if) it has a bounded sequence with no weak-Cauchy subsequence. The proof yields that a sequence of subsets of a given set has a subsequence that is either convergent or Boolean independent.

The N-extended supersymmetric self-dual Poincaré supergravity equations provide a natural local description of supermanifolds possessing hyperkähler structure. These equations admit an economical formulation in chiral superspace. A reformulation in harmonic superspace encodes self-dual supervielbeins and superconnections in a graded skew-symmetric supermatrix superfield prepotential satisfying ...

We consider QED in a constant axial vector background. Lorentz invariance violation(LIV) occurs through radiative corrections. A detailed study of the phenomenology of the model is carried out, clarifying important issues related to the various regularizations employed . In this context, the physical meaning of the cutoffs induced by LIV is emphasized. Finally, finite temperature radiative corr...

In this work, we use Lorentz invariance violation (LIV) introduced as a generic modification to particle dispersion relations to study some consequences of single photon emission, known as vacuum Cherenkov radiation, and photon decay processes in cosmic and gamma rays. These processes are forbidden in a Lorentz invariant theory but allowed under the hypothesis of LIV. We show that the emission ...

In this paper, we study the properties of the generalized harmonic numbersHn,k,r(α, β). In particular, by means of the method of coefficients, generating functions and Riordan arrays, we establish some identities involving the numbers Hn,k,r(α, β), Cauchy numbers, generalized Stirling numbers, Genocchi numbers and higher order Bernoulli numbers. Furthermore, we obtain the asymptotic values of s...

This paper is contributed to the Cauchy problem  ∂u ∂t = ∆u+K(|x|)u p in R × (0, T ), u(x, 0) = φ(x) in R, (0.1) with initial function φ 6≡ 0. The stability and instability of the positive radical steady states, which are positive solutions of ∆u+K(|x|)u = 0, (0.2) has been discussed with different assumption on K(x) and φ under the norm ∗Research supported in part by the Natural Science...

We consider the equation n X k=0 ak(t)x (n−k)(t) = 0, t ≥ 0, where a0(t) ≡ 1, ak(t) (k = 1, . . . , n) are real bounded functions. Assuming that all the roots of the polynomial zn+a1(t)zn−1+· · ·+an(t) (t ≥ 0) are real, we derive positivity conditions for the Green function for the Cauchy problem. We also establish a lower estimate for the Green function and a comparison theorem for solutions.