Magnon-Phonon Quantum Correlation Thermometry

A large fraction of quantum science and technology requires low-temperature environments such as those afforded by dilution refrigerators. In these cryogenic environments, accurate thermometry can be difficult to implement, expensive, and often requires calibration to an external reference. Here, we theoretically propose a primary thermometer based on measurement of a hybrid system consisting of phonons coupled via a magnetostrictive interaction to magnons. Thermometry is based on a cross-correlation measurement in which the spectrum of back-action driven motion is used to scale the thermomechanical motion, providing a direct measurement of the phonon temperature independent of experimental parameters. Combined with a simple low-temperature compatible microwave cavity readout, this primary thermometer is expected to become a promising alternative for thermometry below 1 K

Cosmology in GSG

We describe what cosmology looks like in the context of the geometric theory of gravity (GSG) based on a single scalar field. There are two distinct classes of cosmological solutions. An interesting feature is the possibility of having a bounce without invoking exotic equations of state for the cosmic fluid. We also discuss cosmological perturbation and present the basis of structure formation by gravitational instability in the framework of the geometric scalar gravity.Comment: 12 pages, 5 figures, accepted for publication in Phys. Rev.

More about scalar gravity

We discuss a class of models for gravity based on a scalar field. The models include and generalize the old approach by Nordstr\"om which predated and in some way inspired General Relativity. The class include also a model that we have recently introduced and discussed in its cosmological aspects (GSG). We present here a complete characterisation of the Schwarschild geometry as a vacuum solution of GSG and sketch a discussion of the first Post-Newtonian approximation.Comment: 11 pages, 1 figure, accepted for publication in PR

Geometric scalar theory of gravity

We present a geometric scalar theory of gravity. Our proposal will be described using the "background field method" introduced by Gupta, Feynman and others as a field theory formulation of general relativity. We analyze previous criticisms against scalar gravity and show how the present proposal avoids these difficulties. This concerns not only the theoretical complaints but also those related to observations. In particular, we show that the widespread belief of the conjecture that the source of scalar gravity must be the trace of the energy-momentum tensor - which is one of the main difficulties to couple gravity with electromagnetic phenomenon in previous models - does not apply to our geometric scalar theory. Some consequences of the new scalar theory are explored.Comment: We did some modifications which do not change the content of the tex

Maximal correlation between flavor entanglement and oscillation damping due to localization effects

Localization effects and quantum decoherence driven by the mass-eigenstate wave packet propagation are shown to support a statistical correlation between quantum entanglement and damped oscillations in the scenario of three-flavor quantum mixing for neutrinos. Once the mass-eigenstates that support flavor oscillations are identified as three-{\em qubit} modes, a decoherence scale can be extracted from correlation quantifiers, namely the entanglement of formation and the logarithmic negativity. Such a decoherence scale is compared with the coherence length of damped oscillations. Damping signatures exhibited by flavor transition probabilities as an effective averaging of the oscillating terms are then explained as owing to loss of entanglement between mass modes involved in the relativistic propagation.Comment: 13 pages, 03 figure

Tratamento do problema de contato-impacto entre corpos flexíveis em grandes deformações pelo método dos elementos finitos

O tratamento do problema de contato entre corpos flexíveis foi implementado no módulo METAFOR4, que permite o tratamento de problemas de conformacáo mecanica. O presente algoritmo emprega o método da penalidade para o cálculo de forcas de contato. Os elementos de contato sáo percorridos duas vezes em cada passo de tempo para que seja assegurada a deteccáo de todas as formas de interpenetracao. O algoritmo apresentou-se extremamente robusto. Um exemplo de impacto entre um tubo e uma placa é mostrado.The treatment of the contact problem between flexible bodies has been implemented in the METAFOR modulus4, which allows the treatment of metal forming problems. The described algorithm uses the penalty method for the calculation of the contact forces. The contact elements are checked twice at each time step to assure the detection of al1 forms of penetration. The algorithm demonstrated to be extremely robust. An example of impact between a tube and a plate is given.Peer Reviewe

Tratamento do problema de contato-impacto entre corpos flexíveis em grandes deformações pelo método dos elementos finitos

O tratamento do problema de contato entre corpos flexíveis foi implementado no módulo METAFOR4, que permite o tratamento de problemas de conformacáo mecanica. O presente algoritmo emprega o método da penalidade para o cálculo de forcas de contato. Os elementos de contato sáo percorridos duas vezes em cada passo de tempo para que seja assegurada a deteccáo de todas as formas de interpenetracao. O algoritmo apresentou-se extremamente robusto. Um exemplo de impacto entre um tubo e uma placa é mostrado.The treatment of the contact problem between flexible bodies has been implemented in the METAFOR modulus4, which allows the treatment of metal forming problems. The described algorithm uses the penalty method for the calculation of the contact forces. The contact elements are checked twice at each time step to assure the detection of al1 forms of penetration. The algorithm demonstrated to be extremely robust. An example of impact between a tube and a plate is given.Peer Reviewe