We study the low-energy effective field equations that couple gravity, the dilaton, and the bulk closed string tachyon of bosonic closed string theory. We establish that whenever the tachyon induces the rolling process, the string metric remains fixed while the dilaton rolls to strong coupling. For negative definite potentials we show that this results in an Einstein metric that crunches the un...

We study the full bosonic spectrum around giant and dual giant graviton probes in exactly marginally deformed backgrounds. Considering supersymmetric and non–supersymmetric three–parameter deformations of AdS5 × S, we perform a detailed analysis of small fluctuations for both the expanded D3–brane configurations. In particular, we enhance the scalar spectra of frequencies found in our previous ...

Some basic topics in Light-Front (LF) quantized field theory are reviewed. Poincarè algebra and the LF Spin operator are discussed. The local scalar field theory of the conventional framework is shown to correspond to a nonlocal Hamiltonian theory on the LF in view of the constraint equations on the phase space, which relate the bosonic condensates to the non-zero modes. This new ingredient is ...

Recently, it has been shown that the massless Schwinger model, namely two-dimensional massless spinor electrodynamics, may be solved exactly through the bosonisation of the massless fermion without having recourse to any gauge fixing procedure. With this background in mind, and the possible resolution of massless scalar electrodynamics in two-dimensional Minkowski spacetime compactified into th...

We present a general master equation describing the quantum dynamics of scalar bosonic field interacting with an external weak and stochastic gravitational field. The predicts decoherence both in position energy momentum. show how reproduces, thus generalizing, previous results literature by taking appropriate limits. estimate effect atom interferometers, providing also straightforward way to a...

In the first part, the second quantization procedure and the free Bosonic scalar field will be introduced, and the axioms for quantum fields and nets of observable algebras will be discussed. The second part is mainly devoted to an illustration of the BisognanoWichmann theorem for Wightman fields and in the algebraic setting, with a discussion on the physical meaning of this result. In the thir...

We present the Hamiltonian formulation of the Dirichlet p-brane action. We rewrite the recently proposed quadratic D-brane action in terms of generalized shift vector and lapse function. The first class and the second class constraints are explicitly seperated for the bosonic case. We then impose the gauge conditions in such a way that only time-independent gauge transformations are left. In th...

Using the recently discovered connection between bosonization and duality transformations, we give an explicit path-integral representation for the bosonization of a massive fermion coupled to a U(1) gauge potential (such as electromagnetism) in d ≥ 2 space (D = d + 1 ≥ 3 spacetime) dimensions. We perform this integral explicitly in the limit of large fermion mass. We find that the bosonic theo...

Explicit exact formulas are presented, up to fourth order in a chiral covariant derivative expansion, for the normal parity component of the Euclidean effective action of even-dimensional Dirac fermions. The bosonic background fields considered are scalar, pseudo-scalar, vector and axial vector. No assumptions are made on the internal symmetry group and, in particular, the scalar and pseudo-sca...