Yukawa–Casimir wormholes

In this work, we consider a Yukawa modification of the Casimir wormhole. With the help of an Equation of State, we impose Zero Tidal Forces. We will examine two different approaches: in a first approach, we will fix the form of the shape function of the Casimir wormholes modified by a Yukawa term in three different ways and finally a superposition of different profiles. In the second approach, we will consider the original Casimir source modified by a Yukawa term in three different ways and we will deduce the form of the shape function In both the approaches the reference energy density will be that of the Casimir source. Connection with the Absurdly Benign Traversable Wormhole are also discussed.

Massless fermions localization on domain walls

Massless fermions on scalar domain walls are considered. Two walls are established, corresponding to 5-dimensional static spacetime asymptotically Anti de-Sitter, differentiated by the symmetry around the wall, and in each case massless chiral fermions are coupled to the wall by a Yukawa term. We identify a normalizable state associated to the migration of fermions toward the edge of the wall. This effect is generated by the competition between the Yukawa interaction and the gravitational repulsion on the matter fields, and it is independent of the $Z_2$ symmetry of the wall.

Quasimolecular nuclear potential and its application to 12C +16O reaction near and above the Coulomb barrier

The quasimolecular potential in the sudden approximation is used both near and above the Coulomb barrier (CB) for the [Formula: see text] system. It is found that the resonances associated with the dinuclear configuration are well produced in energy above the CB. Near and below the CB where adiabatic potential is appropriate, it was found that the potential can also be used, provided the potential parameters are varied and the range parameter of the Yukawa term is increased. Resonance positions for [Formula: see text] and 11 agree with experimental findings. The [Formula: see text] resonance energy and width very near 9[Formula: see text]MeV and not at 8.8[Formula: see text]MeV is also reproduced thus supporting experimental results.

YUKAWA CORRECTIONS TO THE NEWTONIAN GRAVITATIONAL POTENTIAL: FINITE SIZE EFFECTS IN A RECENT EXPERIMENT

We provide a formalism to calculate the effect of the finite size of the sample on hypothetical Yukawa-like corrections to the Newtonian gravitational potential. It is explicitly shown that finite size effect contributions are negligible when the extent of the sample is larger than the range of the Yukawa term. In particular we show that these contributions are small in the configuration of a recent experiment. In the experiment a gold coated sphere was moved across the interface between two materials with different mass densities. In view of these new experimental results, we analyze the situation when the error on the hypothetical correction could result to be significant.

YUKAWA CORRECTIONS TO THE NEWTONIAN GRAVITATIONAL POTENTIAL: FINITE SIZE EFFECTS IN A RECENT EXPERIMENT

We provide a formalism to calculate the effect of the finite size of the sample on hypothetical Yukawa-like corrections to the Newtonian gravitational potential. It is explicitly shown that finite size effect contributions are negligible when the extent of the sample is larger than the range of the Yukawa term. In particular we show that these contributions are small in the configuration of a recent experiment. In the experiment a gold coated sphere was moved across the interface between two materials with different mass densities. In view of these new experimental results, we analyze the situation when the error on the hypothetical correction could result to be significant.

ACCELERATED EXPANSION IN MODIFIED GRAVITY WITH A YUKAWA-LIKE TERM

We discuss the Palatini formulation of modified gravity including a Yukawa-like term. It is shown that in this formulation, the Yukawa term offers an explanation for the current exponential accelerated expansion of the universe and reduces to the standard Friedmann cosmology in the appropriate limit. We then discuss the scalar-tensor formulation of the model as a metric theory and show that the Yukawa term predicts a power-law acceleration at late-times. The Newtonian limit of the theory is also discussed in context of the Palatini formalism.

RESTRICTED PROBLEM OF THREE BODIES WITH NEWTONIAN + YUKAWA POTENTIAL

Trajectories of the third body in the Restricted Problem of Three Bodies including a Yukawa term to the Newtonian gravitational potential are analyzed. It is shown that this modified gravitational potential changes some important aspects of the Restricted Problem of Three Bodies. Depending of coupling constant α, motions obtained in the pure Newtonian case are qualitatively different when Yukawa term is included. Depending of coupling parameters α, the nature of dynamics change from regular to chaotic (α<0) or from chaotic to regular (α>0) and in both cases using the same length scales λ.

QUANTUM-MECHANICAL DETECTION OF NON-NEWTONIAN GRAVITY

In this work the possibility of detecting the presence of a Yukawa term, as an additional contribution to the usual Newtonian gravitational potential, is introduced. The central idea is to analyze the effects at quantum level employing interference patterns (at this respect the present proposal resembles the Colella, Overhauser and Werner experiment), and deduce from it the possible effects that this Yukawa term could have. We will prove that the corresponding interference pattern depends on the phenomenological parameters that define this kind of terms. Afterwards, using the so-called restricted path integral formalism, the case of a particle whose position is being continuously monitored, is analyzed, and the effects that this Yukawa potential could have on the measurement outputs are obtained. This allows us to obtain another scheme that could lead to the detection of these terms. This last part also renders new theoretical predictions that could enable us to confront the restricted path integral formalism against some future experiments.

MASS PROTECTION VIA TRANSLATIONAL INVARIANCE

We propose a way of protecting a Dirac fermion interacting with a scalar field from acquiring a mass from the vacuum. It is obtained through an implementation of translational symmetry when the theory is formulated with a momentum cutoff, which forbids the usual Yukawa term. We consider that this mechanism can help to understand the smallness of neutrino masses without a tuning of the Yukawa coupling. The prohibition of the Yukawa term for the neutrino forbids at the same time a gauge coupling between the right-handed electron and neutrino. We prove that this mechanism can be implemented on the lattice.