Design of a Quantum Source of High-Frequency Gravitational Waves (HFGW) and Test Methodology

The generation of High-Frequency Gravitational Waves (HFGW) has been identified as the required breakthrough that will lead to new forms of space propulsion. Many techniques have been devised to generate HFGW, but most of them exhibit marginal efficiency, therefore the power emitted in form of gravitational waves (GW) is orders of magnitude lower than the input power. The gravitational wave counterpart of the LASER, termed Gravitational-wave LASER or "GASER" is the quantum approach to the efficient generation of gravitational waves. Electrons, protons, muons, etc, all have charge and mass, if accelerated they usually lose energy through the very fast electric and magnetic channels, this causes a negligible emission through the gravitational channel. Quantum systems can be engineered to forbid electric and magnetic transitions, therefore the gravitational spin-2 transitions can take place. A class of active materials, suitable for making a GASER based on electronic transitions in the solid state, is identified along with their relevant physical properties. Means for creating coherence and population inversion and means to increase the emission probability are described. The expected performances of the device are derived from quantum gravitational theories. Additional properties of the active materials are considered to enforce the theoretical foundation of the device. A proof-of-concept device, operating at about 1 THz, is described. Experiments are proposed as a natural starting point of the research.Comment: CP699, Space Technology and Applications International Forum-STAIF 2004, proceedings published by AIP and edited by M.S. El-Gen

Why we live in the Computational Universe

To better understand the deep significance of our best physical theories it could be interesting to compare our Universe with its models. It may happen that the differences between the model and reality can be made indistinguishable, to the point that it may seem acceptable to consider reality as a gigantic program, a 'mother computation' running in a Universal Computer. The computational interpretation of reality is here adopted for introducing concepts that are common in computer science, they may offer a new insight. For instance, code and memory usage optimization techniques are common in computer science because they improve the performances at a reduced hardware cost. According to the concepts discussed in this paper, the possibility of recognizing the effects of optimization rules in a physical reality will allow us to discriminate if our reality is fundamental or the result of a large computation. Conversely, code and memory optimization has side effects, if it is present in our Universe it can produce many interesting phenomena, some seem readily recognizable, others only wait to be discovered.Comment: This is an excerpt from an article accepted by Space Technology and Applications International Forum (STAIF 2006) February 12-16, 2006, Albuquerque Hilton Hotel. Space applications omitted. Title changed accordingly. 6 pages with 1 figure added for version

Exact design solutions for photodiode transimpedance amplifiers based on FET input OP-AMPs

We calculate the transfer function of an optical receiver composed by a photodiode and a FET input operational amplifier as a current to voltage converter. According to the theory of low-pass filters, the receiver bandwidth and quality factor are here analytically evaluated, proposing design solutions and their related sensitivity to eventual parameter fluctuations. We exemplify the combined action of photodetection and filtering comparing the analytical expression with full numerical SPICE simulations

Effect of the Vacuum Energy Density on Graviton Propagation

It is known that the value L of the vacuum energy density affects the propagation equation for gravitons: A mass term appears in the propagation equation, such that m^2=-L. As a consequence, the polarization states of gravitons also change. This effect of the L-term has been confirmed by recent calculations in a curved background, which is the only proper setting, since solutions of the classical Einstein equations in the presence of a L-term represent a space with constant curvature. A real value for the mass (when L<0) will show up as a slight exponential damping in the gravitational potential, which is however strongly constrained by astronomical data. The consequences of an imaginary mass (for L>0) are still unclear; on general grounds, one can expect the onset of instabilities in this case. This is also confirmed by numerical simulations of quantum gravity which became recently available. These properties gain a special interest in consideration of the following. (1) The most recent cosmological data indicate that L is positive and of the order of 0.1 J/m^3. Is this value compatible with a stable propagation of gravitons? (2) The answer to the previous question lies perhaps in the scale dependence of the effective value of L. L may be negative at the small distance/large energy scale at which the quantum behavior of gravitational fields and waves becomes relevant. Furthermore, local contributions to the vacuum energy density (in superconductors in certain states, and in very strong static electromagnetic fields) can change locally the sign of L, and so affect locally the propagation and the properties of gravitons. The graviton wavefunction, for different values of the parameters, may be characterized by superluminal phase velocity or by unitarity only in imaginary valued time.Comment: CP699, Space Technology and Applications International Forum-STAIF 2004, proceedings published by AIP and edited by M.S. El-Gen

I giudici europei di fronte alla crisi economica. WP CSDLE “Massimo D’Antona”.INT – 114/2014 = European judges in the face of the economic crisis. WP CSDLE “Massimo D’Antona”.INT – 114/2014

No abstract

Il problema dell’uguaglianza e il diritto del lavoro flessibile = The problem of equality and flexible labor law. WP C.S.D.L.E. “Massimo D’Antona”.IT – 398/2019

This essay (intended for Studies in honor of Antonio Ruggeri) takes into consideration the relationship between flexible labor law and equality, from a legal point of view as well as an ethical one. In particular, the author deals with the problem of the impotence of the countermeasures adopted by the legal system to counter the inequalities and discrimination produced by precarious work. The author points out that the differences do not automatically produce inequalities, but on the condition that they radically change the traditional approach and start a policy of combating precarious work based on new principles

La Carta Sociale Europea e il diritto del lavoro oggi. WP CSDLE “Massimo D’Antona”.INT – 132/2016 = The European Social Charter and labor law today. WP CSDLE “Massimo D’Antona”.INT – 132/2016

Secondo alcuni studiosi la Carta Sociale Europea sta vivendo una “nuova vita” da quando, finalmente, sono entrati in azione meccanismi (seppure atipici ed imperfetti) attuativi dei diritti sociali fondamentali. E in effetti anche nel diritto del lavoro, dopo un lungo oblio, sembra esserci negli ultimi tempi una maggiore attenzione verso la Carta, che dimostra più vitalità e presenza nel discorso giuridico, in particolare dal momento in cui la legislazione ha imboccato una direzione divaricante rispetto alla tradizionale sua funzione di tutela del “contraente debole”

Crisi economica ed effettività dei diritti sociali in Europa. WP CSDLE “Massimo D’Antona”.INT – 104/2014 = Economic crisis and effectiveness of social rights in Europe. WP CSDLE “Massimo D’Antona”.INT – 104/2014

No abstract

Reddito minimo, disuguaglianze sociali e nuovo diritto del lavoro. Fra passato, presente e futuro = Minimum income, social inequalities and new labor law. Between past, present and future. WP C.S.D.L.E. “Massimo D’Antona”.IT – 389/2019

This critical study concerns the issue of basic income, introduced in Italy by the new government a few months ago. The author inserts the comment on the new law into a broader discourse, which concerns the evolution of labor law. In particular, the author considers the crisis of labor law as an expression of the crisis of economic liberalism and seeks to identify the points of contact between them. The citizenship income, he concludes, can therefore be a starting point for a new labor law, which returns to having a function of protecting the worker