Static Universe Research Articles

Maximum Entropy Principle in Deep Thermalization and in Hilbert-Space Ergodicity

We report universal statistical properties displayed by ensembles of pure states that naturally emerge in quantum many-body systems. Specifically, two classes of state ensembles are considered: those formed by (i) the temporal trajectory of a quantum state under unitary evolution or (ii) the quantum states of small subsystems obtained by partial, local projective measurements performed on their complements. These cases, respectively, exemplify the phenomena of “Hilbert-space ergodicity” and “deep thermalization.” In both cases, the resultant ensembles are defined by a simple principle: The distributions of pure states have maximum entropy, subject to constraints such as energy conservation, and effective constraints imposed by thermalization. We present and numerically verify quantifiable signatures of this principle by deriving explicit formulas for all statistical moments of the ensembles, proving the necessary and sufficient conditions for such universality under widely accepted assumptions, and describing their measurable consequences in experiments. We further discuss information-theoretic implications of the universality: Our ensembles have maximal information content while being maximally difficult to interrogate, establishing that generic quantum state ensembles that occur in nature hide (scramble) information as strongly as possible. Our results generalize the notions of Hilbert-space ergodicity to time-independent Hamiltonian dynamics and deep thermalization from infinite to finite effective temperature. Our work presents new perspectives to characterize and understand universal behaviors of quantum dynamics using statistical and information-theoretic tools. Published by the American Physical Society 2024

Particle Production and Density Fluctuations of Non-classical Inflaton in Coherent Squeezed Vacuum State of Flat FRW Universe

Particle Production and Density Fluctuations of Non-classical Inflaton in Coherent Squeezed Vacuum State of Flat FRW Universe

Barotropic equations of state in 4D Einstein-Maxwell-Gauss-Bonnet stellar distributions

We investigate the role of a linear barotropic equation of state (p=γρ) on the structure of charged stars under higher curvature effects induced by the Gauss-Bonnet invariants in 4 dimensions. Assuming a constant spatially directed potential which gives isothermal behavior in the standard theory, the master equation is solved in terms of hypergeometric functions but a viable model could not be constructed. Setting the temporal potential to a constant, comparable to the defective Einstein static universe, interestingly admits nontrivial nonconstant exact solutions due to the higher curvature terms unlike in general relativity. Next the existence of a one-parameter group of conformal motions in the spacetime geometry was investigated. The master differential equation is solvable exactly in implicit form and explicit solutions are found for special cases. For the case of a stiff fluid p=ρ a stellar model with pleasing physical attributes is found. When the potential is assumed to vary linearly with the radius, an exact incoherent radiation model p=13ρ emerges. The physical properties of both these solutions are analyzed comprehensively with the aid of graphical plots in conjunction with suitably defined parameter spaces. It was found that both exact models passed elementary astrophysical tests for physical plausibility.

Data Analysis of LHC Heavy Ion Collision for QGP Study

Abstract. By recreating the first kind of matter in the history of the universe, the quark-gluon plasma (QGP), through PbPb collisions, scientists can study the state of the early universe after the big bang. In this paper, the data from PbPb collisions collected by the Alice experiment at Large Hardron Collider is analyzed to investigate the properties of the QGP. The team focused on Fourier decomposition of azimuthal and angular correlation analysis, using data at a center-of-mass energy of 5.02 TeV per nucleon pair. The distributions of the transverse momentum p_T, the pseudo-rapidity and the azimuth angle were plotted and analyzed. The shapes of plots didnt perfectly match the predictions because of data fluctuations and the limitations of detectors. However, the trend of positive correlation between the coefficients and the transverse momentum p_T was found. The results confirm previous research findings on the collective motion and anisotropic flow of QGP. The study provides insights into the QGP's behavior and supports the theoretical predictions about its properties.

“Let faith oust fact; let fancy oust memory”: Melville, Media and Narratives

Herman Melville’s birthday (On August 1, 1819) was a foreshadowing gesture of the present special issue, having come out of a long –somewhat protracted— collaboration, which coincides with the original publication of Moby-Dick: The Whale on October 18, 1851. The Journal of Narrative and Language Studies takes the opportunity to celebrate Melville’s resonating myth of the human being at the threshold of posthumanism, which explored the human psyche and mysterious potentials from dignity to evil, having been protracted for centuries but eventually led to oblivion. Since the time when he thoroughly, painstakingly, peculiarly created Moby-Dick” and crafted a world of consuming human desire that represents the universal human condition, readers, writers, and artists have been enormously inspired to envisage, fancy, create, design and produce verbal or nonverbal arts in the form of visual works or other means of imagination.

Metabolic Cinema: From Hollywood to Socialist China

Drawing on Karl Marx’s ecological concepts of the “metabolic rift” and the “emancipation of senses”, this paper explores an alternative ecocinema that integrates the ecological with the social and the economic. Early Hollywood films, such as Sunrise: A Song of Two Humans (1927) and The Good Earth (1937), represent the metabolic rift in human relationships as a byproduct of the metabolic rift with nature created in the process of urbanization; hence, they can be regarded as precursors to an alternative ecocinema, which I refer to as “metabolic cinema”. The Story of the Golden Bell (Jinling Zhuan), a comedy film produced during the Chinese Great Leap Forward in 1958, offers an intriguing case for socialist metabolic cinema as a multisensory medianature that participates in and facilitates the metabolic process between humans and nature, as well as the social metabolism among humans, despite the period’s notorious ecological record. The film not only consciously moves away from the visual-centric model associated with capitalist consumerism by using the aural to rectify the once-aberrant visual but also demonstrates how romantic love, as one of the human senses, must be emancipated along with other senses through denouncing utilitarianism and commercialism and, subsequently, returning to need-based labor as the universal condition for the metabolic interaction between humans and nature.

Unraveling the early universe’s equation of state and primordial black hole production with PTA, BBN, and CMB observations* *Qing-Hua Zhu is Supported by the National Natural Science Foundation of China (12305073). Zhi-Chao Zhao is supported by the National Key Research and Development Program of China (2021YFC2203001) and the National Natural Science Foundation of China (12005016). Sai Wang is partially supported

Pulsar timing array (PTA) data releases show strong evidence for a stochastic gravitational-wave background in the nanohertz band. When the signal is interpreted by a scenario of scalar-induced gravitational waves (SIGWs), we encounter overproduction of primordial black holes (PBHs). We wonder if varying the equation of state (EoS) of the early Universe can resolve this issue and thereby lead to a consistent interpretation of the PTA data. Analyzing a data combination of PTA, big-bang nucleosynthesis, and cosmic microwave background, we find that an epoch with EoS between the end of inflation and the onset of radiation domination can significantly suppress the production of PBHs, leading to alleviation of the PBH-overproduction issue. With the inferred interval at 95% confidence level, our scenario can interpret the PTA data just as well as the conventional scenario of SIGWs produced during the radiation domination.

The weather proxy: the racial technics of algorithmic surveillance

ABSTRACT This article examines the political work performed by the weather within contemporary big data predictive analytics. As a sociotechnical construction, the weather has long served as a predictive medium for forecasting human behaviour across historical contexts in order to reinforce settler colonial and imperial projects of spatial domination. Now, within twenty-first century big data systems, the weather has become a proxy for predicting human activity. Examining industrial materials from the predictive policing software HunchLab and the social media sentiment analysis platform Social Doppler, I argue that the weather proxy underwrites claims to prediction by collapsing the distinction between correlation and causation. Key here is how the proxy remediates the mechanism of impressibility that structured the weather as a racial technique for population management within nineteenth century statistical research. Through the weather proxy, big data programmes channel biopolitical frameworks of impressibility – or impressibility by proxy – in ways that causally bind individual behaviour to group-differentiated vulnerabilities of environmental exposure. At stake is how the weather proxy serves as a universal baseline condition for predicting population-level behaviour, which aims to mitigate accusations of racial bias by deferring to environmental conditions beyond human design. As a cultural construction tied to ubiquity, the weather thus is a rhetorical device that works to legitimate predictive analytics as impartial and universal while simultaneously effacing the violence that inheres within algorithmic technologies. Ultimately, by taking a comparative historical approach to the weather, I argue that we might better grasp the transformations in data science that underpin how ubiquity operates as a site of racial violence within contemporary surveillance systems.

Closed universes in two dimensional gravity

We study closed universes in simple models of two dimensional gravity, such as Jackiw-Teiteilboim (JT) gravity coupled to matter, and a toy topological model that captures the key features of the former. We find there is a stark contrast, as well as some connections, between the perturbative and non-perturbative aspects of the theory. We find rich semi-classical physics. However, when non-perturbative effects are included there is a unique closed universe state in each theory. We discuss possible meanings and interpretations of this observation.

Anisotropic Einstein Universes with a Global Magnetic Field and Sasakian Quasi-Killing Spinors

Abstract We consider an Einstein–Dirac–Maxwell system with two charged massless spinors coupled with an electromagnetic field, and construct a family of exact solutions to the system. The solution spacetime is an anisotropic generalization of the static Einstein universe which has a global cosmic magnetic field generated by the current of the spinors. The magnetic field is a force-free field that has played an important role in the study of cosmic magnetic fields. Our exact solution is regarded as a toy model which describes global cosmic magnetic phenomena in the early universe. The spinors are induced from Sasakian quasi-Killing spinors, and the total Dirac current flows along fibers of the Hopf-fibration. The magnetic field is a contact magnetic field.

Amitriptyline and cholecalciferol amend hippocampal histological structure and myelination during stress in Wistar rats via regulating miR200/BMP4/Olig-2 signaling.

Chronic stress is a universal condition commonly associated with many psychiatric diseases. An extensive body of evidence discussed hippocampal affection upon chronic stress exposure, however, the underlying molecular pathways still need to be identified. We investigated the impact of chronic stress on miR200/BMP/Olig-2 signaling and hippocampal myelination. We also compared the effects of chronic administration of amitriptyline and cholecalciferol on chronically stressed hippocampi. Both amitriptyline and cholecalciferol significantly decreased serum cortisol levels, reduced immobility time in the forced swim test, increased the number of crossed squares in open field test, decreased the hippocampal expression of bone morphogenetic protein 4 (BMP4) and its messenger RNA (mRNA) levels, reduced miR200 expression as compared to untreated chronically stressed rats. Also, both drugs amended the hippocampal neuronal damage, enhanced the surviving cell count, and increased the pyramidal layer thickness of Cornu Ammonis subregion 1 (CA1) and granule cell layer of the dentate gyrus. Cholecalciferol was more effective in increasing the area percentage of myelin basic protein (MBP) and Olig-2 positive cells count in hippocampi of chronic stress-exposed rats than amitriptyline, thus enhancing myelination. We also found a negative correlation between the expression of BMP4, its mRNA, miR200, and the immunoexpression of MBP and Olig-2 proteins. This work underscores the amelioration of the stress-induced behavioral changes, inhibition of miR200/BMP4 signaling, and enhancement of hippocampal myelination following chronic administration of either amitriptyline or cholecalciferol, though cholecalciferol seemed more effective in brain remyelination.

Emergent cosmology in 4D Einstein Gauss Bonnet theory of gravity

In this paper, in an FLRW background and a perfect fluid equation of state, we explore the possibility of the realization of an emergent scenario in a 4D regularized extension of Einstein-Gauss-Bonnet gravity, with the field equations particularly expressed in terms of scalar-tensor degrees of freedom. By assuming non-zero spatial curvature (k = ± 1), the stability of the Einstein static universe (ESU) and its subsequent exit into the standard inflationary scenario is tested through different approaches. In terms of dynamical systems, a spatially closed universe rather than an open universe shows appealing behaviour to exhibit a graceful transition from the ESU to standard cosmological history. We found that under linear homogeneous perturbations, for some constraints imposed on the model parameters, the ESU is stable under those perturbations. Moreover, it is noted that for a successful graceful transition, the equation of state ω must satisfy the conditions −1 < ω < 0 and ω < − 1 for closed and open universes, respectively. Furthermore, the ESU is seen to be neutrally stable under matter perturbation in the Newtonian gauge.

The paradox of awareness of death in parenthood transition—A qualitative study

In the high-income countries of Scandinavia, there is a low statistical risk of death during childbirth. However, awareness of the possibility of death seems to have prevailed. In existential psychology and philosophy, awareness of death is a universal condition in life, and facing the anxiety this awareness might invoke has the potential of being life-invigorating. In a hermeneutic analysis of Qualitative data, generated in a study on new parents’ existential meaning-making, this study aimed to explore awareness of death as experienced in parenthood transition. The results found two overarching themes: Awareness of my own Finitude and Fragility of our loved ones. These were interpreted in existential philosophical and psychological theories, and concludes that awareness of death might signify an existential integration of ‘self’ in the new role of parenthood. Acknowledging these thoughts as healthcare professionals could support the meaning-making of parenthood transition, by normalizing their universal nature.

Rotationally invariant translators of the mean curvature flow in Einstein's static universe

In this paper, we deal with non-degenerate translators of the mean curvature flow in the well-known Einstein's static universe. We focus on the rotationally invariant translators, that is, those invariant by a natural isometric action of the special orthogonal group on the ambient space. In the classification list, there are three space-like cases and five time-like cases. All of them, except a totally geodesic example, have one or two conic singularities. Also, we show a uniqueness result based on the behaviour of the translator on its boundary. As an application, we extend an isometry of the sphere to the whole translator under simple conditions. This leads to a characterization of a bowl-like example.

Mass generation via nonlinear massive solution in Higgs potential and particle creations

The nonlinear massive plane wave solution of the classical scalar field in the Higgs potential is revisited to study the mass generation and particle creation. In particular, by assuming that the Higgs system is in the slightly excited state in early universe and it is described by the nonlinear solution, we study the mass generation mechanism for massive vector bosons and a heavy fermion in the quantum field theory around the nonlinear massive classical field. The nonlinear massive classical solution gives the transition from the vacuum to a pair of vector bosons and fermions. We present the new formulae of the probability density of the production process for particles in the standard model of elementary particle physics. The probability densities of the particle productions vanish when the nonlinear massive solution reduces to the constant solution (the classical vacuum expectation value); while the probability densities are expressed as the function of the free parameter in the classical solution in general case. We discuss the behavior of the probability densities for the three oscillating modes in the classical solution.

Legality of restrictions on the right to freedom of movement in the conditions of armed conflict

The article examines the legitimate conditions for limiting the right to freedom of movement as established by international standards. It was determined that the Universal Declaration of Human Rights contains universal conditions for limiting all rights, without singling out freedom of movement. However, the act establishes general principles such as the exclusivity of restriction terms, formal certainty, and completeness of the list of restriction goals. Later documents supplemented these conditions with the social necessity of the restriction and the proportionality of the means of restriction with their legitimate goals. In the International Covenant on Civil and Political Rights and in Protocol No. 4 of the Convention for the Protection of Human Rights and Fundamental Freedoms, the legitimate purposes of restricting freedom of movement were separately defined. These include the protection of national security, public order, the health or morals of the population, the rights and freedoms of other persons, and the prevention of crimes. These limitations are exhaustive, and national legislation should not go beyond them. The author analyzed the conditions for admissibility of restricting the right to freedom of movement under normal and emergency conditions. It was concluded that general requirements apply to the restriction of the right to freedom of movement during a state of emergency (armed conflict), as well as to restrictions under normal conditions. These requirements include prohibitions of destruction and excessive restriction that would be contrary to international human rights standards, as well as encroachment on the essential content of the right to freedom of movement. The criteria for the admissibility of restrictions on the right to freedom of movement, such as legality, necessity, and legitimacy of the purpose of the restriction, should also be applied. However, under extraordinary conditions, such as a state of emergency, there are increased demands. The right to derogate from international human rights obligations is possible in the presence or imminence of public danger within the limits corresponding to the severity of the situation and according to the procedure of official and public notification. Characteristic signs of restriction of the right to freedom of movement in the conditions of an emergency are their massive but temporary nature.

Confronting Power: Bani Abidi and Performances of Masculinity

Abstract Contemporary Pakistani artist Bani Abidi explores the overlapping and multifaceted relationship between performance, nationalism, and machinations of power. This article focuses on a subset of her work that considers how masculinity relates to these ideas. Specifically, in the works discussed in this article, she interrogates the ways masculinity is produced and maintained, ultimately revealing the hollowness of such performances. Abidi’s own diasporic perspective centres South Asian culture and identities throughout her practice. She draws our attention to universal conditions that govern the world, but does so within a specifically South Asian context. Her work points to the fictive and limiting nature of gender roles, revealing how these performances of political masculinity are legacies of the colonial encounter. By examining how the performance of masculinity operates as a mechanism of power within Abidi’s work, this article uncovers how her work addresses displays of nationalism in Pakistan and India, particularly as it relates to the region’s post colonial history.

Knowledge without Epistemology

The universality of scientific principles, theories, laws is never purely “objective”, it has a strong anthropological component. A theory of knowledge invoking transhistorical agencies is therefore not only dead — it was never alive; its so-called successes are nothing but an immense chimera. Scientific research knows no universal boundary conditions or standards whether of a conventional, aprioristic, or empirical kind but uses and invents rules according to circumstance without regarding the selection as a separate “epistemic” act and often without realising that an important choice is being made.

Translators of the Mean Curvature Flow in Hyperbolic Einstein's Static Universe

In this study, we deal with non-degenerate translators of the mean curvature flow in the well-known hyperbolic Einstein's static universe. We classify translators foliated by horospheres and rotationally invariant ones, both space-like and time-like. For space-like translators, we show a uniqueness theorem as well as a result to extend an isometry of the boundary of the domain to the whole translator, under simple conditions. As an application, we obtain a characterization of the the bowl when the boundary is a ball, and of certain translators foliated by horospheres whose boundary is a rectangle.

Review on Minimally Extended Varying Speed of Light Model

It is known that dimensional constants, such as ℏ, c, G, e, and k, are merely human constructs whose values and units vary depending on the chosen system of measurement. Therefore, the time variations in dimensional constants lack operational significance due to their dependence on these dimensional constants. They are well structured and represent a valid discussion. However, this fact only becomes a meaningful debate within the context of a static or present Universe. As theoretically and observationally well established, the current Universe is undergoing accelerated expansion, wherein dimensional quantities, like the wavelength of light, also experience redshift phenomena elongating over cosmic time. In other words, in an expanding Universe, dimensional quantities of physical parameters vary with cosmic time. From this perspective, there exists the possibility that dimensional constants, such as the speed of light, could vary with the expansion of the Universe. In this review paper, we contemplate under what circumstances the speed of light may change or remain constant over cosmic time and discuss the potential for distinguishing these cases observationally.