Related papers: Joseph Polchinski: A Biographical Memoir

This is an expanded version of a talk given at ``{\em IInd Recontre du Vietnam}'' held at Ho Chi Minh City in October, 1995. We discuss several aspects of black hole entropy in string theory. We first explain why the geometric entropy in…

We derive exact gravitational fields of a black hole and a relativistic particle stuck on a codimension-2 brane in $D$ dimensions when gravity is ruled by the bulk $D$-dimensional Einstein-Hilbert action. The black hole is locally the…

In this contribution we report about Feynman's approach to gravitation, starting from the records of his interventions at the Chapel Hill Conference of 1957. As well known, Feynman was concerned about the relation of gravitation with the…

In this continuation of [L-Y1], [L-L-S-Y], [L-Y2], and [L-Y3] (arXiv:0709.1515 [math.AG], arXiv:0809.2121 [math.AG], arXiv:0901.0342 [math.AG], arXiv:0907.0268 [math.AG]), we study D-branes in a target-space with a fixed $B$-field…

In this work, Podolsky theory, a second-order, Lorentz- and gauge-invariant extension of classical electrodynamics, is considered. The effects of Podolsky's modification on fundamental phenomena such as the Stefan-Boltzmann law and the…

We use the recently discovered universality of Einstein equations in the first order formalism to suggest a positive definite Euclidean action. Possible implications for quantum gravity are considered. We discuss the Hawking and Coleman…

Theoretical considerations of fundamental physics, as well as certain cosmological observations, persistently point out to permissibility, and maybe necessity, of macroscopic modifications of the Einstein general relativity. The…

We revisit the effective field theory of long relativistic strings such as confining flux tubes in QCD. We derive the Polchinski-Strominger interaction by a calculation in static gauge. This interaction implies that a non-critical string…

Some seventy five years ago, the concept of dark matter was introduced by Zwicky to explain the anomaly of galactic rotation curves, though there is no clue to its identity or existence to date. In 1997, the author had introduced a model of…

Quasi-topological theories of gravity are known to resolve black-hole singularities. We investigate whether the same mechanism can remove cosmological singularities. Focusing on non-polynomial curvature quasi-topological gravities in $d=4$…

This is a brief overview of researches of Dmitry Petrovich Zhelobenko (1934--2006). He is the best known for his book "Compact Lie groups and their representations" and for the classification of all irreducible representations of complex…

In May 2022 ICRANet organized the Workshop dedicated to the 80th anniversary of Professor Ruffini. This paper is based on the talk delivered at the meeting. Professor Ruffini was well known for Soviet scientific community not only due to…

I share some memories and offer a personal perspective on Jacob Bekenstein's legacy, focussing on black hole entropy and the Bekenstein bound. I summarize a number of fascinating recent developments that grew out of Bekenstein's pioneering…

We consider the motion of charged point particles on Minkowski spacetime. The questions of whether the self-force is finite and whether mass renormalisation is necessary are discussed within three theories: In the standard Maxwell vacuum…

As quotient spaces, Minkowski and de Sitter are fundamental spacetimes in the sense that they are known "a priori", independently of Einstein equation. They represent different non-gravitational backgrounds for the construction of physical…

We explore the cosmological implications provided by the geodetic brane gravity action corrected by an extrinsic curvature brane term, describing a codimension-1 brane embedded in a 5D fixed Minkowski spacetime. In the geodetic brane…

We expand the study of generalized brane cosmologies by allowing for an $f(\tilde{\cal R})$ gravity term on the brane, with $\tilde{\cal R}$ the curvature scalar derived from the induced metric. We also include arbitrary matter components…

We consider a blown-up 3-brane, with the resulting geometry R^(3,1) \times S^(N-1), in an infinite-volume bulk with N > 2 extra dimensions. The action on the brane includes both an Einstein term and a cosmological constant. Similar setups…

I describe the recent progress in resolving two problems of nonperturbative bosonic string inherited from 1980's. Both the lattice and KPZ-DDK no-go theorems can be bypassed thanks to specific features of the theory with diffeomorphism…

Two of the major achievements of Stephen Hawking are described in elementary terms. They are his work on the beginning of the universe and his work on the end of black holes. These are perhaps the scientific achievements for which he is…