Tags » Mathematical Physics

Cascading Multicriticality in Nonrelativistic Spontaneous Symmetry Breaking [CL]


Without Lorentz invariance, spontaneous global symmetry breaking can lead to multicritical Nambu-Goldstone modes with a higher-order low-energy dispersion $\omega\sim k^n$ ($n=2,3,\ldots$), whose naturalness is protected by polynomial shift symmetries. 66 more words

Cosmology And Nongalactic Astrophysics

Self-accelerated universe induced by repulsive effects as an alternative to dark energy and modified gravities [CL]


The existence of current-time universe’s acceleration is usually modeled by means of two main strategies. The first makes use of a dark energy barotropic fluid entering \emph{by hand} the energy-momentum tensor of Einstein’s theory. 218 more words

Cosmology And Nongalactic Astrophysics

Image of the week: turbulent transition

This week’s image is a snapshot of flow visualisation in the study of direct numerical simulation (DNS) of forced isotropic turbulence.

The first figure depicts a typical chaotic turbulent field, while the second figure, taken some time later, shows the velocity and vorticity vectors more aligned after self-organisation. 101 more words

Image Of The Week

A geometrical approach to gravitational lensing magnification [CL]


The standard definition of gravitational lensing magnification is generalized to Lorentzian spacetimes, and it is shown how it can be interpreted geometrically in terms of the van Vleck determinant and the exponential map. 36 more words

Astrophysics Of Galaxies

First articles for R J Baxter's 75th birthday issue are in!

Join us as we explore some of the latest developments in exactly solved models in statistical mechanics inspired by the remarkable work of Rodney Baxter. His illustrious findings, including the invention of powerful techniques for calculating physical properties and solutions to key models, have provided a platform upon which many further advances in mathematical physics have grown. 167 more words

Journal Of Physics A: Mathematical And Theoretical

The geometry of gravitational lensing magnification [CL]


We present a definition of unsigned magnification in gravitational lensing valid on arbitrary convex normal neighborhoods of time oriented Lorentzian manifolds. This definition is a function defined at any two points along a null geodesic that lie in a convex normal neighborhood, and foregoes the usual notions of lens and source planes in gravitational lensing. 77 more words

Astrophysics Of Galaxies