We prove dispersive estimates at low frequency in dimensions n ≥ 4 for the wave equation for a very large class of real-valued potentials, provided the zero is neither an eigenvalue nor a resonance. This class includes potentials V ∈ L∞(R) satisfying V (x) = O ( 〈x〉−(n+1)/2−ǫ ) , ǫ > 0.

We estimate the di-photon coupling of f0(600), f0(980) and f2(1270) resonances in a couple channel dispersive approach. Especially we estimate the di-photon coupling of the third sheet pole located near K̄K threshold, denoted as f III 0 (980). It is argued that this third sheet pole may be originated from a couple channel Breit-Wigner description of the f0(980) resonance. The f0(600) di-photon c...

Article history: Received 11 October 2013 Received in revised form 14 July 2014 Accepted 19 August 2014 Available online 28 August 2014

in this paper, we obtain a suitable mathematical model for the seismic response of dams. by using the shear beam model (sb model), we give a mathematical formulation that it is a partial differential equation and transform it to the sturm-liouville equation.

The presented method of investigating the solutions to differential equations is not new. Such an approach was developed by Cartan [1] in his analysis of the integrability of differential equations. Here this approach is outlined to demonstrate the role of skew-symmetric differential forms. The role of skew-symmetric differential forms in a qualitative investigation of the solutions to differen...

This equation has been of interest in general relativity in various contexts, as well as some other fields of theoretical physics, for over twenty years. One derivation was given by one of us and Charles Boyer[1] in 1982, showing that it determines all self-dual, vacuum solutions of the Einstein field equations which admit a rotational Killing vector. (The description of that metric is given in...

We generalize a recent model-independent form factor parameterization derived from rigorous dispersion relations to include constraints from data in the timelike region. These constraints dictate the convergence properties of the parameterization and appear as sum rules on the parameters. We further develop a new parameterization that takes into account finiteness and asymptotic conditions on t...

The Callan-Treiman low-energy theorem offers an opportunity to test electroweak couplings of light quarks to the gauge boson W. To that aim, we introduce a model-independent and accurate dispersive parametrization of the two K ℓ3 form factors. We then discuss three applications to the analysis of K e3 and K µ3 measurements: the prediction of the ratios Γ K µ3 /Γ (K e3), the extraction of | f + ...

The Callan-Treiman low-energy theorem offers an opportunity to test electroweak couplings of light quarks to the gauge boson W. To that aim, we introduce a model-independent and accurate dispersive parametrization of the two K ℓ3 form factors. We then discuss three applications to the analysis of K e3 and K µ3 measurements: the prediction of the ratios Γ K µ3 /Γ (K e3), the extraction of | f + ...