Objective Reduction Research Articles

Landscape and environmental heterogeneity support coexistence in competitive metacommunities

Metapopulation models have been instrumental in quantifying the ecological impact of landscape structure on the survival of a focal species. However, extensions to multiple species with arbitrary dispersal networks often rely on phenomenological assumptions that inevitably limit their scope. Here, we propose a multilayer network model of competitive dispersing metacommunities to investigate how spatially structured environments impact species coexistence and ecosystem stability. We introduce the concept of landscape-mediated fitness, quantifying how fit a species is in a given environment in terms of colonization and extinction. We show that, when all environments are equivalent, one species excludes all the others-except the marginal case where species fitnesses are in exact trade-off. However, we prove that stable coexistence becomes possible in sufficiently heterogeneous environments by introducing spatial disorder in the model and solving it exactly in the mean-field limit. Crucially, coexistence is supported by the spontaneous localization of species through the emergence of ecological niches. We show that our results remain qualitatively valid in arbitrary dispersal networks, where topological features can improve species coexistence by buffering competition. Finally, we employ our model to study how correlated heterogeneity promotes spatial ecological patterns in realistic terrestrial and riverine landscapes. Our work provides a framework to understand how landscape structure enables coexistence in metacommunities by acting as the substrate for ecological interactions.

Automated Influence and Value Collapse

Abstract Automated influence is one of the most pervasive applications of artificial intelligence in our day-to-day lives, yet a thoroughgoing account of its associated individual and societal harms is lacking. By far the most widespread, compelling, and intuitive account of the harms associated with automated influence follows what I call the control argument. This argument suggests that users are persuaded, manipulated, and influenced by automated influence in a way that they have little or no control over. Based on evidence about the effectiveness of targeted advertising as well as empirical results about the nature of attentional control, I provide reasons to reject this argument. In turn, I use C. Thi Nguyen's theory of value collapse to develop a new account of the harmfulness of automated influence.

Why the Fermi paradox may not be well explained by Wong and Bartlett's theory of civilization collapse. A Comment on: 'Asymptotic burnout and homeostatic awakening: a possible solution to the Fermi paradox?' (2022) by Wong and Bartlett.

Wong and Bartlett explain the Fermi paradox by arguing that neither human nor extra-terrestrial civilizations can escape the time window singularity which, they claim, results from the way in which social characteristics of civilizations follow super-linear growth curves of cities. We question if data at the city level necessarily can lead to conclusions at the civilization level. More specifically, we suggest ways in which learnings from research, foresight, diversity and effective future government might act outside of their model to regulate super-linear growth curves of civilizations, and thus substantively increase the likelihood of civilizations progressing towards higher levels of the Kardashev scale. Moreover, we believe their claimed history of the collapse of terrestrial societies used to evidence their model is difficult to justify. Overall, we cast reasonable doubt on the ability of their proposed model to satisfactorily explain the Fermi paradox.

Causal fermion systems as an effective collapse theory

Abstract It is shown that, in the non-relativistic limit, causal fermion systems give rise to an effective collapse theory. The nonlinear and stochastic correction terms to the Schr"odinger equation are derived from the causal action principle. The dynamics of the statistical operator is described by a deterministic equation of Kossakowski-Lindblad form. Moreover, the quantum state undergoes a dynamical collapse compatible with the Born rule. The effective model has similarities with the continuous spontaneous localization model, but differs from it by a conservation law for the probability integral as well as a non-locality in time on a microscopic length scale~$\ell_{\min}$.

Hardy inequalities for large fermionic systems

Given 0<s<\frac{d}{2} with s\leq 1 , we are interested in the large N -behavior of the optimal constant \kappa_{N} in the Hardy inequality \sum_{n=1}^{N} (-\Delta_{n})^{s} \geq \kappa_{N} \sum_{n<m}|X_{n}-X_{m}|^{-2s} , when restricted to antisymmetric functions. We show that N^{1-\frac{2s}{d}}\kappa_{N} has a positive, finite limit given by a certain variational problem, thereby generalizing a result of Lieb and Yau related to the Chandrasekhar theory of gravitational collapse.

Noninterferometric rotational test of the continuous spontaneous localization model: Enhancement of the collapse noise through shape optimization

Noninterferometric rotational test of the continuous spontaneous localization model: Enhancement of the collapse noise through shape optimization

The Hidden Clash: Spacetime Outlook and Quantum-State Reductions

It is generally assumed that compatibility with special relativity is guaranteed by the invariance of the fundamental equations of quantum physics under Lorentz transformations and the impossibility of transferring energy or information faster than the speed of light. Despite this, various contradictions persist, which make us suspect the solidity of that compatibility. This paper focuses on collapse theories—although they are not the only way of interpreting quantum theory—in order to examine what seems to be insurmountable difficulties we encounter when trying to construct a space–time picture of such typically quantum processes as state vector reduction or the non-separability of entangled systems. The inescapable nature of such difficulties suggests the need to go further in the search for new formulations that surpass our current conceptions of matter and space–time.

Influence of the relative stiffness of second-neighbor interactions on chaotic discrete breathers in a square lattice

It is known that the modulational instability of a delocalized nonlinear vibrational mode (DNVM) with frequency outside the phonon band can lead to spontaneous energy localization in a nonlinear lattice on chaotic discrete breathers (CDBs). Considering a β-FPUT square lattice with nearest and next-nearest interactions, the appearance of CDBs is analyzed for different stiffnesses of the first- and second-nearest interactions, k1 and k2, keeping the density of the lattice unchanged. There are two DNVMs in the square lattice with frequencies above the phonon spectrum and both are studied. The appearance of CDBs in the lattice is monitored by calculating the time evolution of the energy localization parameter L and the maximum energy of the particles emax. For solid state physics and materials science, the important range of stiffness parameters is k2<k1, since the stiffness of chemical bonds typically decreases with the distance between atoms. It is found that CDBs form in the square lattice when k2>k1/4. This means that they can form in crystals if the stiffness of the second-neighbor bonds is smaller than that of the first-neighbor bonds, but not too small. Depending on the relation between the anharmonicity parameters of the first- and second-neighbor bonds CDBs can have different polarization.

Experimental bounds on linear-friction dissipative collapse models from levitated optomechanics

Abstract Collapse models constitute an alternative to quantum mechanics that solve the well-know quantum measurement problem. In this framework, a novel approach to include dissipation in collapse models has been recently proposed, and awaits experimental scrutiny. Our work establishes experimental bounds on the so-constructed linear-friction dissipative Diósi-Penrose (dDP) and Continuous Spontaneous localisation (dCSL) models by exploiting experiments in the field of levitated optomechanics. Our results in the dDP case exclude collapse temperatures below 10−13 K and 6 × 10 − 12 K respectively for values of the localisation length smaller than 10−6 m and 10−8 m. In the dCSL case the entire parameter space is excluded for values of the temperature lower than 6 × 10 − 9 K.

THE IMPLICATIONS OF ARMS PROLIFERATION AND INSECURITY ON HUMAN SECURITY IN AFRICA: A CASE STUDY OF MALI AND NIGERIA

Mali and Nigeria are both faced with the presence of insurgencies, militia, terrorism and other violent non-state actors (VNSAs), who perpetrate large-scale violence; thus, creating daunting security challenges in these countries. This goes pari passu with the proliferation of small arms and light weapons (SALWs) in these countries. While these countries have inherent human security challenges, this spate of insecurity will not only inhibit the quest for human security, but further deteriorate it. Thus, this paper examines the interrelationship between arms proliferation, violent conflicts and insecurity in these countries and their implication on human security. The study is anchored on the State Collapse theory and the Ex-post Facto research design. The Documentary Observation method of data is utilised; hence, data is generated from secondary sources such as academic publications, organisational publications, databases, etc. For data analysis, the study adopts the Causal Analysis and Process Tracing methods of data analysis. The study found that the proliferation of SALWs and violent conflicts complement each other in Mali and Nigeria, thus, creating high-scale insecurity challenges in both countries. It also found that the implications of this state of affairs on human security are enormous in these countries; particularly in the aspects of physical security, food security, economic security, environmental security and political security. On these bases, the study advocates for relevant stakeholders such as the governments, ECOWAS, religious organisations and traditional institutions to play key roles in addressing the menace

Stochastic field dynamics in models of spontaneous unitarity violation

Objective collapse theories propose a solution to the quantum measurement problem by predicting deviations from Schrödinger’s equation that can be tested experimentally. A class of objective theories based on spontaneous unitarity violation was recently introduced, in which the stochastic field required for obtaining Born’s rule does not depend on the state of the system being measured. Here, we classify possible models for the stochastic field dynamics in theories of spontaneous unitarity violation. We show that for correlated stochastic dynamics, the field must be defined on a closed manifold. In two or more dimensions, it is then always possible to find stochastic dynamics yielding Born’s rule, independent of the state being measured or the correlation time of the stochastic field. We show that the models defined this way are all isomorphic to the definition on a two-sphere, which we propose to be a minimal physical model for the stochastic field in models of spontaneous unitarity violation.

A Dynamic Network Model of Societal Complexity and Resilience Inspired by Tainter's Theory of Collapse.

In recent years, several global events have severely disrupted economies and social structures, undermining confidence in the resilience of modern societies. Examples include the COVID-19 pandemic, which brought unprecedented health challenges and economic disruptions, and the emergence of geopolitical tensions and conflicts that have further strained international relations and economic stability. While empirical evidence on the dynamics and drivers of past societal collapse is mounting, a process-based understanding of these dynamics is still in its infancy. Here, we aim to identify and illustrate the underlying drivers of such societal instability or even collapse. The inspiration for this work is Joseph Tainter's theory of the "collapse of complex societies", which postulates that the complexity of societies increases as they solve problems, leading to diminishing returns on complexity investments and ultimately to collapse. In this work, we abstract this theory into a low-dimensional and stylized model of two classes of networked agents, hereafter referred to as "laborers" and "administrators". We numerically model the dynamics of societal complexity, measured as the fraction of "administrators", which was assumed to affect the productivity of connected energy-producing "laborers". We show that collapse becomes increasingly likely as the complexity of the model society continuously increases in response to external stresses that emulate Tainter's abstract notion of problems that societies must solve. We also provide an analytical approximation of the system's dominant dynamics, which matches well with the numerical experiments, and use it to study the influence on network link density, social mobility and productivity. Our work advances the understanding of social-ecological collapse and illustrates its potentially direct link to an ever-increasing societal complexity in response to external shocks or stresses via a self-reinforcing feedback.

The tragedy of the commodity and the state: a comparative case study of the Atlantic bluefin tuna and Newfoundland cod fishery collapses

The world’s oceans face total ecological collapse by 2048 if the fishing industries’ extraction is not reined in. At the helm of the ocean crisis have been fisheries management regimes built upon the logic of the tragedy of the commons, which interpret resource depletion as being driven by human self-interest, and then ­propose market-based policy solutions. This comparative case study tests the generalizability of the tragedy of the commodity, a political economic theory of fishery collapse that challenges the tragedy of the commons by applying it to the case of the 1992 Newfoundland cod fishery collapse. A model for incorporating a distinct analysis of state structures, actions, and interests is then proposed.

Eternal inflation and collapse theories

The eternal inflation problem continues to be considered one of standard's cosmology most serious shortcomings. This arises when one considers the effects of “quantum fluctuations” on the zero mode of inflaton field during a Hubble time in the inflationary epoch.In the slow-roll regime it is quite clear that such quantum fluctuations could dwarf the classical rolling down of the inflaton, and with overwhelming probability this prevents inflation from ever ending. When one recognizes that quantum fluctuations can not be taken as synonymous of stochastic fluctuations, but rather intrinsic levels of indefiniteness in the quantities in question, one concludes that the eternal inflation problem simply does not exist. However, the same argument would serve to invalidate the account for the generation of the primordial seeds of cosmic structure as has been amply discussed elsewhere [1,2,3]. In order to do address that issue, one must explain the breaking of homogeneity and isotropy of the situation prevailing during the early inflationary epoch (at both the quantum and classical levels of the description). For that one needs to rely on some additional element, beyond those present in the traditional treatments. The so called spontaneous collapse theories offer a viable candidate for that element, namely the stochastic and spontaneous state reduction characteristic of those proposals possesses the basic features to break those symmetries. In fact, a version of the CSL theory adapted to the cosmological context has been shown to offer a satisfactory account for the origin the seeds of cosmic structure with an adequate power spectrum [2], and will serve as the basis of our analysis. However, once such stochastic collapse is introduced into the theoretical framework the eternal inflation problem has the potential reappear.In this manuscript we explore those issues in detail and discuss an avenue that seems to allow for a satisfactory account for the generation of the primordial inhomogeneities and anisotropies while freeing the theory from the eternal inflation problem.

Characterizing the spontaneous collapse of a wavefunction through entropy production

We investigate the phenomenology leading to the non-conservation of energy of the continuous spontaneous localization (CSL) model from the viewpoint of non-equilibrium thermodynamics, and use such framework to assess the equilibration process entailed by the dissipative formulation of the model (dCSL). As a paradigmatic situation currently addressed in frontier experiments aimed at investigating possible collapse theories, we consider a one-dimensional mechanical oscillator in a thermal state. We perform our analysis in the phase space of the oscillator, where the entropy production rate, a non-equilibrium quantity used to characterize irreversibility, can be conveniently analyzed. We show that the CSL model violates Clausius law, as it exhibits a negative entropy production rate, while the dCSL model reaches equilibrium consistently only under certain dynamical conditions, thus allowing us to identify the values—in the parameter space—where the latter mechanism can be faithfully used to describe a thermodynamically consistent phenomenon.

Observational constraints on the second-order primordial power spectrum: Exploring a Continuous Spontaneous Localization inspired inflationary model

Inflation, a period of exponential expansion in the early Universe, is considered an important part of the standard ΛCDM cosmological model, and plays a crucial role in explaining a wide range of current observations. The standard inflationary model predicts a primordial spectrum of fluctuations that is nearly scale-independent, fitting remarkably well the latest observational data. Nevertheless, there is an ongoing discussion surrounding the transition from an initial homogeneous and isotropic quantum state, characterizing the matter fields during inflation, to a classical inhomogeneous/anisotropic one, which gives rise to large-scale structure in the Universe. To tackle this issue, in the present work we explore an inflationary scenario where quantum “collapse” (or reduction) occurs naturally during the evolution of the system; this model is inspired in the so called Continuous Spontaneous Localization (CSL) model. Our present work builds upon previous results by considering the primordial power spectrum up to the second order in the Hubble Flow Functions, where we perform an estimation of the model free parameters. By validating the predictions of the model against observational data, we investigate whether this second-order calculation can explain the slight departure from the power law observed in the scalar spectral running index. We hope this research contributes to the understanding of the quantum-to-classical transition and its implications for cosmology.

The Collapse of Democracy in Chile

The study of the de-democratization occurring in emerging democracies is one of the key research topics in comparative political science. Some scholars have found that the breakdown of democracy is related to some social structural factors. For example, the inequality of economic development, the degree of political fragmentation of the electorate, and the political institutional arrangements of democracies. Other scholars argue that the collapse of democracy is the result of the actions and choices of political elites. In order to preserve their wealth and status, political elites formed powerful coalitions to undermine democracies, which led to the reversal of democracy into authoritarian regime. Yet there is no single explanation for Chile's democratic collapse. Therefore, this study reviews the literature on the theory of democratic collapse, and analyzes the causes of the democratic collapse in Chile by combining the economic and social conditions of Chile in 1973. The research finds that Chile's democratic collapse is the result of a combination of elite revolt behavior and centrifugal political institutional arrangements. The intense class conflict violates the interests of the political elite and causes the political elite to rebel. At the same time, the centrifugal arrangement of the political system has left the state and the government lacking the ability to effectively counter the revolt behavior of the political elite.

Spontaneous localisation from a coarse-grained deterministic and non-unitary dynamics

Collapse of the wave function appears to violate the quantum superposition principle as well as deterministic evolution. Objective collapse models propose a dynamical explanation for this phenomenon, by making a stochastic non-unitary and norm-preserving modification to the Schrödinger equation. In the present article we ask how a quantum system evolves under a deterministic and non-unitary but norm-preserving evolution? We show using a simple two-qubit model that under suitable conditions, quantum linear superposition is broken, with the system predictably driven to one or the other eigenstates. If this deterministic dynamics is coarse-grained and observed over a lower time resolution, the outcomes appear random while obeying the Born probability rule. Our analysis hence throws light on the distinct roles of non-unitarity and of stochasticity in objective collapse models.

Is Superluminal Signaling Possible in Collapse Theories of Quantum Mechanics?

Is Superluminal Signaling Possible in Collapse Theories of Quantum Mechanics?

Asymmetry and evolution of craton-influenced rifted margins

Abstract Rifting can result in asymmetric conjugate margins. In numerical models with laterally homogeneous lithosphere, the polarity of the asymmetry is random and results from spontaneous strain localization on a dominant fault/shear zone. However, along the central South Atlantic, margin width is well correlated to the proximity of the rift to a craton during rifting. To understand the evolution of rifting close to a craton, we used numerical experiments that included a thick craton lithosphere adjacent to a thinner, mobile-belt lithosphere. When rifting starts close to the craton, i.e., ≤ 100 km, deformation focuses along a fault/shear zone dipping toward the craton, leading to cratonward asymmetric asthenospheric uplift and rift migration. This results in a narrow margin on the craton side and a wide margin on the mobile-belt side. Craton-related asymmetry results in the wide margin subsiding more than the narrow one, inducing the formation of large synrift sag basins in the wide conjugate, as in the South Atlantic. This differential subsidence is preserved for ~100 m.y. after breakup and may partly explain the present-day higher dynamic topography close to cratons in the central South Atlantic. Mantle flow during asymmetric rifting leads to weakening of the craton lithosphere, partial intermixing, and recycling into the convective mantle, as interpreted for this sector of the South Atlantic ridge. Thus, rifting adjacent to a craton may have wide-ranging tectonic, stratigraphic, and compositional consequences that affect not only margin architecture, but also the development of subsequent dynamic topography and the spreading system.