Search results for "Einstein"

Making Mathematics in an Oral Culture: Göttingen in the Era of Klein and Hilbert

2004

This essay takes a close look at specially selected features of the Göttingen mathematical culture during the period 1895–1920. Drawing heavily on personal accounts and archival resources, it describes the changing roles played by Felix Klein and David Hilbert, as Göttingen's two senior mathematicians, within a fast-growing community that attracted an impressive number of young talents. Within the course of these twenty-five years Göttingen exerted a profound impact on mathematics and physics throughout the world. Many factors contributed to the creation of a special atmosphere that served as a model for several other important centers for mathematical research. Göttingen exemplified a dyna…

Analysis and calibration of absorptive images of Bose-Einstein condensate at non-zero temperatures

2008

We describe the method allowing quantitative interpretation of absorptive images of mixtures of BEC and thermal atoms which reduces possible systematic errors associated with evaluation of the contribution of each fraction. By using known temperature dependence of the BEC fraction, the analysis allows precise calibration of the fitting results. The developed method is verified in two different measurements and compares well with theoretical calculations and with measurements performed by another group.

The Sax Mission for X-Ray Astronomy

1990

The satellite for X-ray astronomy SAX, to be launched at the end of 1993, is devoted to systematic, integrated and comprehensive, studies of galactic and extra-galactic sources in the energy band 0.1–200 keV, and is under joint development by the Italian Space Agency (ASI) and the Netherlands Agency for Aerospace programs (NIVR), with the participation of SRU/SRON and SSD/ESTEC. The basic scientific objectives can be summarized as follows: — Broad band spectroscopy (E/△ E=12) from 0.1–10 keV with imaging resolution of 1 arcmin. — Continuum and line spectroscopy (E/△ E=5-20) in the energy range 3–200 keV. — Variability studies of bright source energy spectra on timescales from milliseconds t…

Nodal solitons and the nonlinear breaking of discrete symmetry

2005

We present a new type of soliton solutions in nonlinear photonic systems with discrete point-symmetry. These solitons have their origin in a novel mechanism of breaking of discrete symmetry by the presence of nonlinearities. These so-called nodal solitons are characterized by nodal lines determined by the discrete symmetry of the system. Our physical realization of such a system is a 2D nonlinear photonic crystal fiber owning C6v symmetry.

A duality-invariant Einstein-Planck relation and its consequences on micro-black holes.

2013

We discuss the consequences of a duality-invariant Einstein–Planck (DIEP) relation on the equation of state of micro black holes. The results are analogous to those obtained from the "world-crystal" model, but with some significative differences, as for instance a limiting vanishing value for temperature for very small black holes. The model leads to a total evaporation of micro black holes but with the final stage being very slow.

Imperfect symmetry breaking

2018

By considering a nonlinear resonator driven by an elliptically polarized beam, we study experimentally the robustness of spontaneous symmetry breaking to controlled asymmetries. In particular, we reveal that different asymmetries can balance each other.

Spotlighting phase separation in Rashba spin-orbit coupled Bose–Einstein condensates in two dimensions

2018

Quantum Einstein Gravity: Towards an Asymptotically Safe Field Theory of Gravity

2007

“The Important Thing is not to Stop Questioning”, Including the Symmetries on Which is Based the Standard Model

2014

New fundamental physical theories can, so far a posteriori, be seen as emerging from existing ones via some kind of deformation. That is the basis for Flato’s “deformation philosophy”, of which the main paradigms are the physics revolutions from the beginning of the twentieth century, quantum mechanics (via deformation quantization) and special relativity. On the basis of these facts we describe two main directions by which symmetries of hadrons (strongly interacting elementary particles) may “emerge” by deforming in some sense (including quantization) the Anti de Sitter symmetry (AdS), itself a deformation of the Poincare group of special relativity. The ultimate goal is to base on fundame…

Comment on “Einstein-Gauss-Bonnet Gravity in Four-Dimensional Spacetime”

2020

We argue that several statements in Phys. Rev. Lett. 124, 081301 (2020) are not correct.