Related papers: Reply to "Comment to a paper of M. Villata on anti…
Points of conflict between the principles of general relativity and quantum theory are highlighted. I argue that the current language of QFT is inadequete to deal with gravity and review attempts to identify some of the features which are…
Recent review article by S. Samuel "On the speed of gravity and the Jupiter/Quasar measurement" published in the International Journal of Modern Physics D13, 1753 (2004) provides the reader with a misleading "theory" of the relativistic…
I address the problem of indefiniteness in quantum mechanics: the problem that the theory, without changes to its formalism, seems to predict that macroscopic quantities have no definite values. The Everett interpretation is often…
We consider the interaction of gravity, as expressed by Einstein's Equations of General Relativity, to other force fields. We describe some recent results, discussing both the mathematics, and the physical interpretations. These results…
Reply to the Comment physics/0307134 by A. Helmstetter and D. Sornette
Clement and Noiucer submitted a note {\tt arXiv:2401.16008 [gr-qc]} replying to our criticism {\tt arXiv:2401.10479 [gr-qc]} of their previous submission. We reply to the contents of this note and remark that these authors have not…
We reply to David's comment (hep-lat/9504017) on our paper Phys.Rev.Lett. 74(1995)1920.
We briefly review ideas about ``noncommutativity of space-time'' and approaches toward a corresponding theory of gravity.
Possibility of gravitational repulsion in General Relativity is discussed and astronomical data in favor of cosmological acceleration are described. The problem of vacuum energy is emphasized and possible ways of its solution are indicated.…
This is an informal review of the formulation of canonical general relativity and of its implications for quantum gravity; the various versions are compared, both in the continuum and in a discretized approximation suggested by Regge…
The questions I have been asked during the 5th International School on Field Theory and Gravitation, have compelled me to give an account of the premises that I consider important for a beginner's approach to Loop Quantum Gravity. After a…
The Weak Gravity Conjecture holds that gravity must be the weakest force. This is true of the familiar forces in our own universe -- electromagnetism, for instance, is many orders of magnitude stronger than gravity. But the bold claim of…
This is an introduction to quantum gravity, aimed at a fairly general audience and concentrating on what have historically two main approaches to quantum gravity: the covariant and canonical programs (string theory is not covered). The…
This is a contribution to a book on quantum gravity and philosophy. I discuss nature and origin of the problem of quantum gravity. I examine the knowledge that may guide us in addressing this problem, and the reliability of such knowledge.…
On his way to General Relativity (GR) Einstein gave several arguments as to why a special relativistic theory of gravity based on a massless scalar field could be ruled out merely on grounds of theoretical considerations. We re-investigate…
Recollections on how the basic concepts and ingredients of supergravity were formulated by Dmitrij V. Volkov and the present author in 1973-74.
In their recent paper [Phys. Rev. Lett. 98, 094101 (2007)], A. Porporato et al. studied the irreversibility and fluctuation theorem for stationary time series. In this comment, we point out that the fluctuation theorem is in fact the…
In order to clarify why the zero-point energy associated with the vacuum fluctuations cannot be a candidate for the dark energy in the universe, a comparison with the Casimir effect is analyzed in some detail. A principle of epistemology is…
A recent paper by Gambini, Rastgoo and Pullin [arXiv:1106.1417 investigates the important issue of constraints from Lorentz invariance on Planck scale physics, arguing that the classic analysis of Collins, Perez, Sudarsky, Urrutia and…
A flaw is pointed out in the justification given by Charitat and Graner [2003 Eur. J. Phys. vol. 24, 267] for the use of the Biot--Savart law in the calculation of the magnetic field due to a straight current-carrying wire of finite length.