# Category Archives: Physics

## The microscopic mechanism behind the vibrational relaxation of adsorbates on metal surfaces

Most of the theories describing dynamical processes at surfaces rely on the validity of the adiabatic Born-Oppenheimer approximation. What does this mean? We have already seen that adsorption commonly is understood as the reversible binding of molecules and atoms […]

## Remarks on Moduli Spaces and String Theory

The concept of moduli space is of utmost relevance in theoretical physics and mathematics, especially in geometry, topology and string theory. A moduli space is, roughly speaking, a space that classifies a given class of objects modulo an equivalence […]

## The flexibility of 2D silica

Since the discovery that graphene, the two dimensional carbon allotrope, can be isolated and incorporated into electronic devices intense research efforts have been triggered. Driving forces usually mentioned behind the experimental and theoretical studies of graphene are the exceptional electronic […]

## How to extract the interacting spectral function from a ground state DFT calculation

The electronic wave function of an n-electron molecule depends on 3n spatial and n spin coordinates. In a sense, the wave function of a many-electron molecule contains more information than is needed and is lacking in direct physical significance. This […]

## Higher-order topological insulators

Topological insulators are materials with special universal properties, which are protected against perturbations. Such properties are theoretically described by topology, a branch of mathematics concerned with the properties of geometrical objects that are unchanged by continuous deformations. Concretely, topological insulators […]

## Our current image of atoms

The wave–particle dualism is a fundamental aspect of quantum mechanics. But, in order to explore this dualism properly and what it means for our image of atoms, it is necessary to review some ideas of probability.

In some situations, no […]

## The size of atoms, uncertainty and relativity

You may have read somewhere that atoms are actually made up mostly of empty space. The usual description goes more or less as follows. At the centre of each atom there is a very tiny nucleus, which carries all of […]

## Family unification (2): The SO(18) spinor strikes back

In the previous post, Family unification 1, we reviewed the historical development of Grand Unified Theories (GUT) of force and matter, i.e. Comprehensive Unification. We saw how the SO(18) spinor, 256, is able to accomodate the Standard Model […]

## Attoscience using X-ray free-electron lasers

How long does it take a photon to split a molecule? It is apparent that the answer must be well bellow a second, but, how much bellow? Attoscience focuses on these kind of phenomena that occur at the attosecond time-scale […]

## Accurate simulation of aqueous-based electrochemical setups

Following the need for new and renewable sources of energy worldwide, fuel cells using electrocatalysts can be thought of as viable options. Catalyst materials modify and increase the rate of chemical reactions without itself undergoing any permanent change. An electrocatalyst […]