We extend strong/weak coupling duality to string theories without spacetime supersymmetry, and focus on the case of the unique ten-dimensional, nonsupersymmetric, tachyon-free SO(16)×SO(16) heterotic string. We construct a tachyon-free heterotic string model that interpolates smoothly between this string and the ten-dimensional supersymmetric SO(32) heterotic string, and we construct a dual for...

The thermofield dynamics of the D = 10 heterotic thermal string theory is described in proper reference to the thermal duality symmetry as well as the thermal stability of modular invariance in association with the global phase structure of the D = 10 heterotic thermal string ensemble.

We study the quantum energy of the Z-string in 2+1 dimensions using the phase shift formalism. Our main interest is the question of stability of a Z-string carrying a finite fermion number. PACS numbers: 03.65Sq, 03.70+k, 05.45.Yv, 11.27.+d

Some issues on the stability of black string or brane solutions are summarized briefly. The stability of dS/AdS-Schwarzschild black strings has been investigated. Interestingly, the AdS-Schwarzschild black strings turn out to be stable as the horizon size becomes larger than the AdS scale. It is also shown that BTZ black strings in four dimensions are stable regardless of the horizon size. Such...

We find supertubes with arbitrary (and not necessarily planar) cross-section; the stability against the D2-brane tension is due to a compensation by the local momentum generated by Born-Infeld fields. Stability against long-range supergravity forces is also established. We find the corresponding solutions of the N = ∞ M(atrix) model. The supersymmetric D2/D2 system is a special case of the gene...

This thesis studies metaand exactly stable supersymmetry breaking mechanisms in heterotic and type IIB string theories and constructs an F-theory Grand Unified Theory model for neutrino physics in which neutrino mass is determined by the supersymmetry breaking mechanism. Focussing attention on heterotic string theory compactified on a 4-torus, stability of non-supersymmetric states is studied. ...

For vehicle platoons, the leader following control architecture is known to be capable of achieving string stability while maintaining tight formations. In this paper we study a variety of schemes where the leader state is available to the other members of the platoon. We show that in some cases it is possible to achieve string stability in the presence of certain amounts of time delay in the l...

A structural transition for laser cooled ion Coulomb crystals in a linear Paul trap just above the stability limit of parametrically resonant excitation of bulk plasma modes has been observed. In contrast to the usual spheroidal shell structures present below the stability limit, the ions arrange in a "string-of-disks" configuration. The spheroidal envelopes of the string-of-disks structures ar...

Cooperative Adaptive Cruise Control (CACC) is considered as a key enabling technology to automatically regulate the intervehicle distances in a vehicle platoon to improve traffic efficiency while maintaining safety. Although the wireless communication and physical processes in the existing CACC systems are integrated in one control framework, the coupling between wireless communication reliabil...