The determination of near-surface attenuation for hard rock sites is an important issue in a wide range of seismological applications, particularly seismic hazard analysis. In this article we choose six hard to very-hard rock sites (Vs30 1030–3000ms–1) and apply a range of analysis methods to measure the observed attenuation at distance based on a simple exponential decay model with whole-p…

In most numerical simulations of the Earth’s core the dynamo resides outside the tangent cylinder and may be crudely classified as being of the α2 type. In this region the flow comprises a sea of thin columnar vortices aligned with the rotation axis, taking the form of alternating cyclones and anticyclones. The dynamo is thought to be driven by these columnar vortices within which the f…

Previous studies of Earth rotation perturbations due to ice-age loading have predicted a slow secular drift of the rotation axis relative to the surface geography (i.e. true polar wander, TPW) of order of several degrees over the Plio-Pleistocene. It has been argued that this drift and the change in the geographic distribution of solar insolation that it impliesmay have been responsible for imp…

A computational method is given for solving the forward modelling problem for transient electromagnetic exploration. Its key features are the discretization of the quasi-static Maxwell’s equations in space using the first-kind family of curl-conforming N´ed´elec elements combined with time integration using rational Krylov methods. We show how rational Krylov methods can also be used to sol…

We have developed a compact permanent-magnet sextupole lens for neutrons that can focus a pulsed beam with a wide wavelength range—the maximum wavelength being more than double the minimum—while sufficiently suppressing the effect of chromatic aberration. The bore diameter is ø15 mm. Three units of a double-ring sextupole with a length of 66mm are cascaded, resulting in a total length of 1…

In this paper we argue that the well-known maximal extensions of the Kerr and Kerr–Newman spacetimes characterized by a specific gluing (on disks) of two asymptotically flat regions with ADM masses of opposite signs are physically inconsistent and actually non-analytic. We also discover a correct geometrical interpretation of the surface r = 0, t = const—a dicone in the case of the Kerr sol…

We calculate the von Neumann entanglement entropy and the Schmidt number of onedimensional (1D) cluster states and show that these are useful measures to estimate entanglement caused by delocalization of clusters. We analyze system size dependence of these entanglement measures in the linear-chain nα states given by Tohsaki–Horiuchi–Schuck–Röpke wave functions for 1D cluster gas st…

Seismic full waveform inversion is an objective method to estimate elastic properties of the subsurface and is an important area of research, particularly in seismic exploration community. It is a data-fitting approach, where the difference between observed and synthetic data is minimized iteratively. Due to a very high computational cost, the practical implementation of waveform inversion has …

We investigate properties of the net baryon number fluctuations near chiral crossover in a hot and dense medium of strongly interacting quarks. The chirally invariant quark–antiquark interactions are modeled by an effective quark–meson Lagrangian. To preserve remnants of criticality in the O(4) universality class, we apply the functional renormalization group method to describe thermodynami…

According to general relativity, a clock experiencing a shift in the gravitational potential ∆U will measure a frequency change given by ∆f/f ≈ ∆U/c2. The best clocks are optical clocks. After about 7 hr of integration they reach stabilities of ∆f/f ∼ 10−18 and can be used to detect changes in the gravitational potential that correspond to vertical disp…