相关论文: Cosmic Strings and the String Dilaton

In the Standard Model, the difference between the baryon number $B$ and the lepton number $L$ is conserved, which represents a symmetry that is global and exact, and therefore unnatural. We turn it into a naturally exact, local symmetry by…

A candidate for the confining string of gauge theories is constructed via a representation of the ultraviolet divergences of quantum field theory by a closed string dilaton insertion, computed through the soft dilaton theorem. The resulting…

The electromagnetic field correlators are evaluated around a cosmic string in background of $(D+1)$-dimensional dS spacetime assuming that the field is prepared in the Bunch-Davies vacuum state. The correlators are presented in the…

In the context of a cosmological string model describing the propagation of strings in a time-dependent Robertson-Walker background space-time, we show that the asymptotic acceleration of the Universe can be identified with the square of…

Cosmic string solutions of the abelian Higgs model with conformal coupling to gravity are shown to exist. The main characteristics of the solutions are presented and the differences with respect to the minimally coupled case are studied. An…

String gas cosmology is rewritten in the Einstein frame. In an effective theory in which a gas of closed strings is coupled to a dilaton gravity background without any potential for the dilaton, the Hagedorn phase which is quasi-static in…

String gas cosmology is an approach towards studying the effects of superstring theory on early universe cosmology which is based on new symmetries and new degrees of freedom of string theory. Within this context, it appears possible to…

Models which accelerate the expansion of the universe through the addition of a function of the Ricci scalar f(R) leave a characteristic signature in the large-scale structure of the universe at the Compton wavelength scale of the extra…

String compactification in the framework of the low energy effective supergravity requires the perturbative control in both the large volume and the weak coupling expansions. However, when the complex structure moduli couple to some lattice…

A generic aspect of low-energy effective field theories (EFTs) coming from string compactifications is the appearance of moduli fields. Among these moduli, the axion and dilaton are present as (pseudo-) Goldstone bosons from the spontaneous…

The gravitational field of both local and global non static cosmic strings in the context of Lyra geometry are investigated. Local strings are characterized by having an energy momentum tensor whose only non null components are $T_{tt} =…

We study the network of Type-I cosmic strings using the field-theoretic numerical simulations in the Abelian-Higgs model. For Type-I strings, the gauge field plays an important role, and thus we find that the correlation length of the…

We present the first complete Markov chain Monte Carlo analysis of cosmological models with evolving cosmic (super)string networks, using the unconnected segment model in the unequal-time correlator formalism. For ordinary cosmic string…

We present cosmic microwave background (CMB) power spectra from recent numerical simulations of cosmic strings in the Abelian Higgs model and compare them to CMB power spectra measured by Planck. We obtain revised constraints on the cosmic…

The Large Volume Scenario for getting a non-supersymmetric vacuum in type IIB string theory leads, through the Weyl anomaly and renormalization group running, to an interesting phenomenology. However, for gravitino masses below 500 TeV…

Although galaxy clusters have proved to be wonderful laboratories for testing a plethora of modified gravity theories and other exotic alternatives to $\Lambda$CDM, until a few years ago, there was only one paper (from 1974), which obtained…

In the modified measure formulation the string tension appear as an additional dynamical degree of freedom and these tensions are not universal, but rather each string generates its own tension, which can have a different value for each…

We study the possibility of canceling the cosmological constant in supergravity string models. We show that with a suitable choice of superpotential the vacuum energy may vanish with the dilaton field at its minimum and supersymmetry broken…

We investigate the spacetime of a spinning cosmic string in conformal invariant gravity, where the interior consists of a gauged scalar field. We find exact solutions of the exterior of a stationary spinning cosmic string, where we write…

String theory has no parameter except the string scale, so a dynamically compactified solution to 4 dimensional spacetime should determine both the Planck scale and the cosmological constant $\Lambda$. In the racetrack K\"ahler uplift flux…