We point out that the universality of free-fall can be tested by observing surface-gravity changes of the Earth. The Earth’s inner core is weakly coupled to the rest part of the Earth by mainly gravitational forces. If there were a violation of the universality of free-fall, because of their different chemical compositions and/or of different mass fractions of binding energies, the inner core a...

Amorphous solids, and many disordered lattices, exhibit a remarkable qualitative and quantitative universality in their acoustic properties at temperature 3 K. This phenomenon is attributed to the existence of tunneling two-level systems (TTLSs), characterized by a homogeneous density of states (DOS) at energies much lower than the disorder energy (≈0.1 eV). Here we calculate numerically, from ...

Renormalization group theory does not restrict the form of continuous variation of critical exponents which occurs in presence of a marginal operator. However, the continuous variation of critical exponents, observed in different contexts, usually follows a weak universality scenario where some of the exponents (e.g., β, γ, ν) vary keeping others (e.g., δ, η) fixed. Here we report ferromagnetic...

A new classification of sandpile models into universality classes is presented. On the basis of extensive numerical simulations, in which we measure an extended set of exponents, the Manna two state model [S. S. Manna, J. Phys. A 24, L363 (1991)] is found to belong to a universality class of random neighbor models which is distinct from the universality class of the original model of Bak, Tang ...