相关论文: Ten Years of the Fifth Force

It has been speculated that gravity could be an emergent phenomenon, with classical general relativity as an effective, macroscopic theory, valid only for classical systems at large temporal and spatial scales. As in classical continuum…

The idea that quantum gravity manifestations would be associated with a violation of Lorentz invariance is very strongly bounded and faces serious theoretical challenges. This leads us to consider an alternative line of thought for such…

We show that a new force, which appeared in a five-dimensional generalization of general relativity, implies precisely the flat circular velocity curves of luminous matter observed in the outer parts of spiral galaxies. A cosmological…

Naturalness has for many years been a guiding principle in the search for physics beyond the Standard Model, particularly for understanding the physics of electroweak symmetry breaking. However, the discovery of the Higgs particle at 125…

Quantum gravity is known to be mostly a kind of metaphysical speculation. In this brief essay, we try to argue that, although still extremely difficult to reach, observational signatures can in fact be expected. The early universe is an…

Neutrinos, and primarily neutrino oscillations, have undoubtedly been one of the most exciting topics in the field of high-energy physics over the past few years. The existence of neutrino oscillations would require an extension of the…

By means of a general classification of the different kinds of matter of nature form a chain from the world of the subatomic particles to the large bodies of the universe, the galaxies. Then, it proposes a new baryonic force for the…

A recently proposed "gedanken experiment" [G.Z. Machabeli and A.D. Rogava. Phys. Rev. A {\bf 50}, 98 (1994)], exhibiting surprising behavior, is reexamined. A description of this behavior in terms of the laboratory inertial frame is…

There has been a recent stimulus in the study of alternative theories of gravity lately, mostly triggered from combined motivation coming from cosmology/astrophysics and high energy physics. Among the proposed theories, one that has…

The problem of the enormous gravitational effects observed by the astronomers in several galactic nuclei with obscure bodies appears puzzling. These bodies are too large to be neutron stars generated by supernovae of primeval stars and are…

We study observational bounds in a class of scalar-tensor gravity theories recently proposed. Either an upper or lower bound on a conformal factor in these theories is derived from null observation in composition dependent fifth force…

Experimental searches for new, "fifth" forces are attracting a lot of attention because they allow to test theoretical extensions to the standard model. Here, we report a new experimental search for possible fifth forces, specifically…

Cosmology, high-energy physics and astrophysics are converging on the study of large-scale magnetic fields. While the experimental evidence for the existence of large-scale magnetization in galaxies, clusters and superclusters is rather…

Large contributions to the near closure of the Universe and to the acceleration of its expansion are due to the gravitation of components of the stress-energy tensor other than its mass density. To familiarise astronomers with the…

Some reflections are presented on the state of the search for a quantum theory of gravity. I discuss diverse regimes of possible quantum gravitational phenomenon, some well explored, some novel.

Time variation of fundamental constants would not be surprising in the framework of theories involving extra dimensions. The variation of any one constant is likely to be correlated with variations of others in a pattern that is diagnostic…

The polynomial affine model of gravity was proposed as an alternative to metric and metric-affine gravitational models. What at the beginning was thought as a source of unpredictability, the presence of many terms in the action, turned out…

Since the seminal work of Verlinde, the idea that gravity may be an emergent force of entropic origin has gained widespread attention. Many generalizations of this key idea have been considered in the literature, starting from well-known…

The distinction between modified gravity and quintessence or dynamical dark energy is difficult. Many models of modified gravity are equivalent to models of coupled quintessence by virtue of variable transformations. This makes an…

We present here a spectrum of developments and predictions in gravitation theory in recent years which appear to be amongst some of the most exciting directions. These include the spacetime singularities, gravitational collapse final…