We present a simple physical mechanism that can account for the observed stellar mass spectrum for masses M∗>∼ 0.5M⊙. The model depends solely on the competitive accretion that occurs in stellar clusters where each star’s accretion rate depends on the local gas density and the square of the accretion radius. In a stellar cluster, there are two different regimes depending on whether the gas or t...

Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass from the surrounding cloud material. This process is investigated, using numerical models of molecular cloud dynamics. Molecular cloud regions without turbulent driving sources, or where turbulence is driven on large scales, exhibit rapid and efficient star formation in a clustered ...

The analysis of the amminoacidic sequence of a peptide is a basic and fundamental issue in Proteomics. Such analysis is generally performed by using Mass Spectrometry equipment. This procedure exhibits several advantages on other methods. In particular, a mass/mass (or tandem mass) analysis is very often used. This latter technique produces a spectrum displaying the molecular weight of the full...

We study T-duality for open strings on tori Td. The general boundary conditions for the open strings are constructed, and it is shown that T-duality group, which preserves the mass spectrum of closed strings, preserves also the mass spectrum of the open strings. The open strings are transformed to those with different boundary conditions by T-duality. We also discuss the T-duality for D-brane m...

We demonstrate that the aperture mass as a measure for cosmic shear closely approximates (to better than ≈ 5%) the scaled and shifted power spectrum of the projected mass density. This cosmological weak-lensing information can thus be used to directly infer the projected matter power spectrum with high accuracy. As an application, we show that aperture-mass observations can be used to constrain...

The energy spectrum of nuclear recoils in Weakly Interacting Massive Particle (WIMP) direct detection experiments depends on the underlying WIMP mass. We study how the accuracy with which the WIMP mass could be determined by a single direct detection experiment depends on the detector configuration and the WIMP properties. We investigate the effects of varying the underlying WIMP mass and cross...

We derive the glueball masses in noncommutative super Yang–Mills theories in four dimensions via the dual supergravity description. The spectrum of glueball masses is discrete due to the noncommutativity and the glueball masses are proportional to the noncommutativity parameter with dimension of length. The mass spectrum in the WKB approximation closely agrees with the mass spectrum in finite t...