The Heidelberg Laureate Forum Foundation presents the HLF Portraits: Edward Witten

# Category Archives: Uncategorized

# Einstein’s biggest mistake?

**Gary J. Ferland**

What, if any, was Einstein’s biggest mistake, the one most affecting our physics today? There is a perhaps apocryphal story, recounted by George Gamow, that he counted his cosmological constant as his biggest blunder. We now know his hypothesized cosmological constant to be correct. His lifelong rejection of quantum mechanics, an interesting side-story in the evolution of 20th-century physics, is a candidate. None of these introduced difficulties in how our physics is done today. It can be argued that his biggest actual mistake, one that affects many subfields of physics and chemistry and bewilders students today, occurred in his naming of his A and B coefficients…

Read more at https://arxiv.org/pdf/1905.09276.pdf

# Gauge Theories and Non Commutative Geometry

Professor John Iliopoulos (ENS Paris)

www.physik.uni-muenchen.de

# Two Notions of Naturalness

**Porter Williams**

My aim in this paper is twofold: (i) to distinguish two notions of naturalness employed in BSM physics and (ii) to argue that recognizing this distinction has methodological consequences. One notion of naturalness is an “autonomy of scales” requirement: it prohibits sensitive dependence of an effective field theory’s low-energy observables on precise specification of the theory’s description of cutoff-scale physics. I will argue that considerations from the general structure of effective field theory provide justification for the role this notion of naturalness has played in BSM model construction. A second, distinct notion construes naturalness as a statistical principle requiring that the values of the parameters in an effective field theory be “likely” given some appropriately chosen measure on some appropriately circumscribed space of models. I argue that these two notions are historically and conceptually related but are motivated by distinct theoretical considerations and admit of distinct kinds of solution.

Read more at https://arxiv.org/pdf/1812.08975.pdf

# Relativistic spring-mass system

The harmonic oscillator plays a central role in physics describing the dynamics of a wide range of systems close to stable equilibrium points. The nonrelativistic one-dimensional spring-mass system is considered a prototype representative of it. It is usually assumed and galvanized in textbooks that the equation of motion of a relativistic harmonic oscillator is given by the same equation as the nonrelativistic one with the mass M at the tip multiplied by the relativistic factor 1/(1−v^{2}/c^{2})^{1/2}. Although the solution of such an equation may depict some physical systems, it does not describe, in general, one-dimensional relativistic spring-mass oscillators under the influence of elastic forces. In recognition to the importance of such a system to physics, we fill a gap in the literature and offer a full relativistic treatment for a system composed of a spring attached to an inertial wall, holding a mass M at the end.

Read more at https://arxiv.org/pdf/1810.13365.pdf

# Quantum treatment of Verlinde’s entropic force conjecture

**A. Plastino, M. C. Rocca, G. L. Ferri**

Verlinde conjectured that gravitation is an emergent entropic force. This surprising conjecture was proved in [Physica A **505** (2018) 190] within a purely classical context. Here, we appeal to a quantum environment to deal with the conjecture in the case of bosons and consider also the classical limit of quantum mechanics (QM)….

Read more at https://arxiv.org/pdf/1808.01330.pdf

# The Hawking temperature, the uncertainty principle and quantum black holes

**Jorge Pinochet**

In 1974, Stephen Hawking theoretically discovered that black holes emit thermal radiation and have a characteristic temperature, known as the Hawking temperature. The aim of this paper is to present a simple heuristic derivation of the Hawking temperature, based on the Heisenberg uncertainty principle. The result obtained coincides exactly with Hawking’s original finding. In parallel, this work seeks to clarify the physical meaning of Hawking’s discovery. This article may be useful as pedagogical material in a high school physics course or in an introductory undergraduate physics course.

Read more at https://arxiv.org/pdf/1808.05121.pdf