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Andrea Gregori

Publications and source records attributed to Andrea Gregori.

At least 19 recordsLinked to original sources
arXiv2012

The superstring representation of the universe of codes

We discuss the continuum field theory limit of the physical scenario described in Ref. [1], the universe arising from the interpretation of the most general collection of logical codes in terms of distributions of units of energy along units of space. This limit leads in a natural way to string theory as the theory which allows to perturbatively parametrize the geometric structures in terms of propagating particles and fields. We discuss some general properties of the spectrum, masses and couplings, the existence of the strong force, with particular attention to the excited states, and the implications for the physics of high energy colliders.

physics.gen-ph↗
arXiv2012

A physical universe from the universe of codes

We investigate the most general phase space of configurations, consisting of the collection of all possible ways of assigning elementary attributes, "energies", to elementary positions, "cells". We discuss how this space defines a "universe" with a structure that can be approximately described by a quantum-relativistic physical scenario in three space dimensions. In particular, we discuss how the Heisenberg's Uncertainty and the bound on the speed of light arise, and what kind of mechanics rules on this space.

physics.gen-ph↗
arXiv2011

A note on the gravity screening in quantum systems

We discuss how, in the theoretical scenario presented in [1], the gravity screening and the gravity impulse which seem to be produced under certain conditions by high temperature superconductors are expected to be an entropic response to the flow of part of the system into a deeper quantum regime.

physics.gen-ph↗
arXiv2011

Combinatorics, observables, and String Theory: part II

We investigate the string configuration that, in the framework of the theoretical scenario introduced in [1], corresponds to the most entropic configuration in the phase space of all the configurations of the universe. This describes a universe with four space-time dimensions, and the physical content is phenomenologically compatible with the experimental observations and measurements. Everything is determined in terms of the age of the universe, with no room for freely-adjustable parameters. We discuss how one obtains the known spectrum of particles and interactions, with massive neutrinos, no Higgs boson, and supersymmetry broken at the Planck scale. Besides the computation of masses and couplings, CKM matrix elements, cosmological constant, expansion parameters of the universe etc..., all resulting, within the degree of the approximation we used, in agreement with the experimental observations, we also discuss how this scenario passes the tests provided by cosmology and the constraints imposed by the physics of the primordial universe.

physics.gen-ph↗
arXiv2011

Combinatorics, observables, and String Theory

We investigate the most general phase space of configurations, consisting of all possible ways of assigning elementary attributes, ``energies'', to elementary positions, ``cells''. We discuss how this space possesses structures that can be approximated by a quantum-relativistic physical scenario. In particular, we discuss how the Heisenberg's Uncertainty Principle and a universe with a three-dimensional space arise, and what kind of mechanics rules it. String Theory shows up as a complete representation of this structure in terms of time-dependent fields and particles. Within this context, owing to the uniqueness of the underlying mathematical structure it represents, one can also prove the uniqueness of string theory.

physics.gen-ph↗
arXiv2010

On the critical temperatures of superconductors: a quantum gravity approach

We consider superconductivity in the light of the quantum gravity theoretical framework introduced in [1]. In this framework, the degree of quantum delocalization depends on the geometry of the energy distribution along space. This results in a dependence of the critical temperature characterizing the transition to the superconducting phase on the complexity of the structure of a superconductor. We consider concrete examples, ranging from low to high temperature superconductors, and discuss how the critical temperature can be predicted once the quantum gravity effects are taken into account.

physics.gen-ph↗
arXiv2010

Is the Universe the only existing Black Hole?

We investigate the physics of black holes in the light of the quantum theoretical framework proposed in [1]. It is argued that black holes are completely non-local objects, and that the only one which really exists is the universe itself.

physics.gen-ph↗
arXiv2010

Beyond Quantum Mechanics and General Relativity

In this note I present the main ideas of my proposal about the theoretical framework that could underlie, and therefore "unify", Quantum Mechanics and Relativity, and I briefly summarize the implications and predictions.

physics.gen-ph↗
arXiv2009

Relativity as classical limit in a combinatorial scenario

We discuss how the finiteness and universality of the speed of light arise in the theoretical framework introduced in [1], and derive generalized coordinate transformations, that allow to investigate physical systems in a non-classical regime.

physics.gen-ph↗
arXiv2009

An Entropy-Weighted Sum over Non-Perturbative Vacua

We discuss how, in a Universe restricted to the causal region connected to the observer, General Relativity implies the quantum nature of physical phenomena and directly leads to a string theory scenario, whose dynamics is ruled by a functional that weights all configurations according to their entropy. The most favoured configurations are those of minimal entropy. Along this class of vacua a four-dimensional space-time is automatically selected; when, at large volume, a description of space-time in terms of classical geometry can be recovered, the entropy-weighted sum reduces to the ordinary Feynman's path integral. What arises is a highly predictive scenario, phenomenologically compatible with the experimental observations and measurements, in which everything is determined in terms of the fundamental constants and the age of the Universe, with no room for freely-adjustable parameters. We discuss how this leads to the known spectrum of particles and interactions. Besides the computation of masses and couplings, CKM matrix elements, cosmological constant, expansion parameters of the Universe etc..., all resulting, within the degree of the approximation we used, in agreement with the experimental observations, we also discuss how this scenario passes the tests provided by cosmology and the constraints imposed by the physics of the primordial Universe.

hep-th↗
arXiv2009

About combinatorics, and observables

We investigate the most general "phase space" of configurations, consisting of all possible ways of assigning elementary attributes, "energies", to elementary positions, "cells". We discuss how this space possesses structures that can be approximated by a quantum physics scenario. In particular, we discuss how the Heisenberg's "Uncertainty Principle" and a "universe" with a three-dimensional space arise, and what kind of mechanics rules it.

hep-th↗
arXiv2007

A note on the phases of natural evolution

The natural evolution of life seems to proceed through steps characterized by phases of relatively rapid changes, followed by longer, more stable periods. In the light of the string-theory derived physical scenario proposed in [1], we discuss how this behaviour can be related to a sequence of resonances of the energy of natural sources of radiation and absorption energies of the DNA, responsible for mutagenesis. In a scenario in which these energy scales run independently as functions of the age of the Universe, the conditions for evolutionary mutagenesis are satisfied only at discrete points of the time axis, and for a short period, corresponding to the width of the resonance. We consider in particular the evolution of the primates through subsequent steps of increasing cranio-facial contraction, and the great Eras of life (Paleozoic, Mesozoic, Cenozoic), showing that the transitions occur at the predicted times of resonance.

physics.gen-ph↗
arXiv2004

Naturally Time Dependent Cosmological Constant

In the light of the proposal of hep-th/0207195, we discuss in detail the issue of the cosmological constant, explaining how can string theory naturally predict the value which is experimentally observed, without low-energy supersymmetry.

hep-th↗
arXiv2002

String-String triality for d=4, Z_2 orbifolds

We investigate the perturbative and non-perturbative correspondence of a class of four dimensional dual string constructions with N=4 and N=2 supersymmetry, obtained as Z_2 or Z_2 x Z_2 orbifolds of the type II, heterotic and type I string. In particular, we discuss the heterotic and type I dual of all the symmetric Z_2 x Z_2 orbifolds of the type II string, classified in hep-th/9901123. .

hep-th↗
arXiv2002

Entropy, String Theory, and our World

We investigate the consequences of two assumptions for String (or M) Theory, namely that: 1) all coordinates are compact and bound by the horizon of observation, 2) the ``dynamics'' of compactification is determined by the ``second law of thermodynamics'', i.e. the principle of entropy. We discuss how this leads to a phenomenologically consistent scenario for our world, both at the elementary particle's and at the cosmological level, without any fine tuning or further ``ad hoc'' constraint.

hep-th↗
arXiv2001

Rank 48 gauge group in heterotic string

We discuss the existence of a non-perturbative gauge sector that can raise the rank of the gauge group of the N_4=2 heterotic string up to 48. These gauge bosons, that don't exist in six dimensions, co-exist with those originating from small instantons shrinking to zero size.

hep-th↗
arXiv2001

The d=6, N=1 heterotic string does not "live" in six dimensions

We discuss why the N_6=1 heterotic string has to be viewed as something similar to a ``non-compact orbifold''. Only the perturbative spectrum is forced to satisfy the constraints imposed by the vanishing of six-dimensional anomalies. These do not apply to the states of the non-perturbative spectrum, such as those appearing when small instantons shrink to zero size.

hep-th↗