Relativistic Spacetime Research Articles

Spherical Accretion in the Schwarzschild Spacetime in the Newtonian Analogous Construct

The velocity-dependent Newtonian analogous potentials (NAPs) corresponding to general relativistic (GR) spacetimes accurately capture most of the relativistic features, including all classical tests of GR, effectively representing spacetime geometries in Newtonian terms. The NAP formulated by Tejeda & Rosswog (TR13) for Schwarzschild spacetime has been applied to the standard thin accretion disk around a black hole (BH) as well as in the context of streamlines of noninteracting particles accreting onto a Schwarzschild BH, showing good agreement with the exact relativistic solutions. As a further application, here we explore the extent to which TR13 NAP could describe a transonic hydrodynamical spherical accretion flow in Schwarzschild spacetime within the framework of standard Newtonian hydrodynamics. Instead of obtaining a typical single “saddle-type” sonic transition, a “saddle–spiral pair” is produced, with the inner sonic point being an (unphysical) “spiral type” and the outer being a usual “saddle type.” The Bondi accretion rate at outer sonic radii, however, remains consistent with that of the GR case. The primary reason for the deviation of our findings from the classical Bondi solution is likely due to the inconsistency between the Euler-type equation in the presence of velocity-dependent TR13 NAP within the standard Newtonian hydrodynamics framework, and the corresponding GR Euler equation, regardless of the fluid’s energy. Our study suggests that a (modified) hydrodynamical formalism is needed to effectively implement such potentials in transonic accretion studies that align with the spirit of TR13 like NAP, while remaining consistent with the GR hydrodynamics. This could then essentially circumvent GR hydrodynamics or GR magnetohydrodynamics equations

Специфика языковой репрезентации пространственно-временной категории в идиостиле Р. О. Батлера

The aim of the research is to reveal the specifics of language representation of the space-time category in R. O. Butler’s idiostyle. The article considers modern approaches to the study of fiction space and time, which are considered as basic textual categories providing a holistic perception of the text. The scientific novelty lies in revealing the specifics of the implementation of space-time relations in the work of the ergodic genre written in the “stream of consciousness” technique. This is the first time that R. Butler’s idiostyle is studied in this aspect. The results of the study have shown that a range of expressive means and devices representing space-time category is used. Among them are techniques of retardation and syntactic anticipation to create the effect of slow perception of time; a wide use of Historical Present to convey the feeling of the Past as if it were the Present; the usage of the lexical units with emotive connotation, rhetorical questions and exclamations and repetitions to convey emotional atmosphere of the described moments; non-linear narrative and limited time space description to create the effect of “reverse photography”; detailed portrait of the nearest items according to the law of aerial and spatial perspective; synthesis of the lexical units conveying visual, audio and tactile space perception.

Anxiety in digital consumer culture: a psychoanalytic reflection on the emergence of a reactive subjectivity

ABSTRACT Anxiety is widely understood to be a harmful consequence of engagement with digital technologies such as social media. Although digital life is studied by cultural consumer researchers, its psychic effects are not well explored. We focus on anxiety as a psychosocial effect of digital consumer culture by elaborating on Teresa Brennan’s theorisation of the connection between technological development, subject formations, and space–time relations. We propose four psychosocial trends that propel anxiety, illustrated by composite narratives: objectification, immediacy, disembodiment, and estrangement. Our narratives emphasise a spatio-temporal shift in how the subject relates to itself and others, conditioning the emergence of a reactive subjectivity driven by self-examination and modification rather than relationality. This offers an understanding of how digital technologies shape subject formations to be anxious, thereby attending to capital interests invested in propelling a reactive state of subjectivity at the expense of the spontaneous, relational experience of being human.

Indonesian Performing Arts in the Era of Covid-19: Digitizing Campus Theatre

Abstract In Indonesia, the Covid-19 pandemic dramatically affected many sectors, in particular modern theatre and higher education institutions that host campus theatres. This study focuses on the strategies employed by campus theatres to survive the pandemic, focusing on digital theatre productions by Petra Theatre (formerly Petra Little Theatre) in Surabaya, Play Performance Class in Yogyakarta, and Teater Kampus in Makassar posted on YouTube in 2020–2022. Taking the perspectives by Matthew Causey on digital performance, supported by Sarah Bay-Cheng’s dramaturgy of distortion of mediated theatre, and by Philip Auslander on liveness in mediatized performance, we analyze the emergence of certain aspects of mediatized/digital theatre that pertain to actor-audience relation and time-space relations exemplified by the digital performance offered by these three campus theatres.

Underdetermination in classic and modern tests of general relativity

Canonically, ‘classic’ tests of general relativity (GR) include perihelion precession, the bending of light around stars, and gravitational redshift; ‘modern’ tests have to do with, inter alia, relativistic time delay, equivalence principle tests, gravitational lensing, strong field gravity, and gravitational waves. The orthodoxy is that both classic and modern tests of GR afford experimental confirmation of that theory in particular. In this article, we question this orthodoxy, by showing there are classes of both relativistic theories (with spatiotemporal geometrical properties different from those of GR) and non-relativistic theories (in which the lightcones of a relativistic spacetime are ‘widened’) which would also pass such tests. Thus, (a) issues of underdetermination in the context of GR loom much larger than one might have thought, and (b) given this, one has to think more carefully about what exactly such tests in fact are testing.

Changes in hydraulic and physico-water parameters of surface waters under the influence of anthropogenic activities in the Western Carpathians

To evaluate the quality of watercourses in the Western part of Carpathians from a hydro-chemical perspective, a systematic approach is required. This involves gradually excluding factors that contribute to the washing, mixing, and transportation of contaminants in the watercourse pathway. The model that considers spatial dependencies by autoregression was implemented in this study to determine the correlation between hydrodynamic and physico-chemical characteristics of waters at surface in different groups and forms of catchment use. The surface water at forested areas had the maximum average shear stress of 0.178 N∙m−2. The watercourse at sustained grassland had the maximum average Reynolds number (Re) of 23,654 and the minimum number of 0.426 at arable lands. Spatial autoregression analysis revealed space-time relations in various measurement points. When constructing the space-physical model, it is important to consider the influence of hydraulic characteristic parameters on the generation of physicochemical indicators in the flysch basin. Specifically, it may be beneficial to take into account the turbulent diffusion coefficient. The autoregression analysis demonstrated that for the ions P-PO43− and K+ in surface water on cropland and for total iron and the cation K+ ion grassland (p < 0.05), the turbulent diffusion coefficient proved to be of great importance. The study did not identify any physicochemical dependency for woodland surface waters. The findings can be utilised to create an erosion model that considers the contribution of material supply in a catchment area, specifically from weathered Carpathian flysch or surface runoff, to the alimentation of alluvial deposits.

GPS observables in Newtonian spacetime or why we do not need ‘physical’ coordinate systems

Some authors have defended the claim that one needs to be able to define ‘physical coordinate systems’ and ‘observables’ in order to make sense of general relativity. Moreover, in Rovelli (Physical Review D,65(4), 044017 2002), Rovelli proposes a way of implementing these ideas by making use of a system of satellites that allows defining a set of ‘physical coordinates’, the GPS coordinates. In this article I oppose these views in four ways. First, I defend an alternative way of understanding general relativity which implies that we have a perfectly fine interpretation of the models of the theory even in the absence of ‘physical coordinate systems’. Second, I analyze and challenge the motivations behind the ‘observable’ view. Third, I analyze Rovelli’s proposal and I conclude that it does not allow extracting any physical information from our models that wasn’t available before. Fourth, I draw an analogy between general relativistic spacetimes and Newtonian spacetimes, which allows me to argue that as ‘physical observables’ are not needed in Newtonian spacetime, then neither are they in general relativity. In this sense, I conclude that the ‘observable’ view of general relativity is unmotivated.

Investigation on hyperbolic Ricci soliton in a perfect fluid spacetime

The aim of this paper is to inspect the geometrical aspects of a perfect fluid spacetime conveying hyperbolic Ricci soliton with torse-forming vector field [Formula: see text]. Next, we have investigated some physical perceptions of perfect fluid spacetime such as dark fluid spacetime, stiff matter fluid spacetime, dust fluid spacetime and radiation fluid spacetime with hyperbolic Ricci soliton in terms of isotropic pressure, the cosmological constant, energy density and gravitational constant. We have also provided two examples of hyperbolic Ricci soliton and hyperbolic Ricci–Bourguignon soliton. Later, we explore the relativistic magneto-fluid spacetime obeying hyperbolic Ricci soliton along with different vector fields.

Pernambuco-Alagoas, Riacho do Pontal, and Sergipano domains of the Borborema Province, Northeastern Brazil: a geological and geochronological synthesis

Abstract In recent years, the number of works seeking to advance the geological and geotectonic knowledge of the Borborema Province has been increasing. However, in the context of the Southern Borborema Province there are few studies aimed at understanding its tectonic evolution in an integrated way. This work presents a review of the lithostratigraphic and geochronological data available for the Pernambuco-Alagoas, Riacho do Pontal and Faixa Sergipana Domains, located in the southern portion of the Borborema Province (Northeast Brazil), in addition to a discussion on the tectonic evolution model. The Southern Borborema Province fully encompasses the state of Alagoas and partially the states of Pernambuco, Sergipe, Bahia and Piauí, and is delimited to the north by the Pernambuco Lineament and to the south by the São Francisco Craton. The methodology involved bibliographical survey, geological cartography, geochronological compilation, creation of detrital zircon histograms for metasedimentary rocks (with unconformity below 10%) and magmatic “barcodes” for ortho-derived rocks and preparation of regional geological profiles. The tectonic evolution of the Southern Borborema Province began with the breakup of the Rodínia Supercontinent (1000 Ma) during the Cariris Velhos Cycle. The processes involved in the interaction of fragments descending from Rodinia are diachronic, in a broad scenario of accretions and collisions that resulted in the merger of Gondwana. The Pernambuco-Alagoas Block is considered a complex tectonic domain, which was affected by the Cariris Velhos (1000 – 950 Ma) and Brasiliana (740 - 570 Ma) orogenies (Caxito & Alkmim 2023), preserving remnants of Archean rocks (Riacho Seco Fragment) and proterozoic. The Riacho do Pontal Domain and the Faixa Sergipana Domain are part of a large folding system formed from the collision of the Pernambuco-Alagoas Domain with the São Francisco Craton, in a tangential deformation, vergent towards the craton, during the Brasiliana Orogeny. From the ages of the syncollisional granites we can infer that the orogenic event that gave rise to the aforementioned folded bands occurred at very close time intervals, presenting a slight diachronism. The article presents an integrated approach to tectonic evolution, however, the need for new studies is quite evident, with an emphasis on isotopic geology, geochronology, geochemistry and geological mapping that can contribute to the understanding of the processes involved in the formation of tectonic domains, their space-time relationships and their implications for the evolution of the Gondwana Continent.

The number of fundamental constants from a spacetime-based perspective

We revisit Duff, Okun, and Veneziano’s divergent views on the number of fundamental constants and argue that the issue can be set to rest by having spacetime as the starting point. This procedure disentangles the resolution in what depends on the assumed spacetime (whether relativistic or not) from the theories built over it. By defining that the number of fundamental constants equals the minimal number of independent standards necessary to express all observables, as assumed by Duff, Okun, and Veneziano, it is shown that the same units fixed by the apparatuses used to construct the spacetimes are enough to express all observables of the physical laws defined over them. As a result, the number of fundamental constants equals one in relativistic spacetimes.

Being-Time, or How Traditional Japanese Thought Collided with Western Philosophy and Modern Physics at Hiroshima

The atom bomb that annihilated Hiroshima, Japan, on August 6, 1945, proved Albert Einstein’s theory of relativity. Mass became energy and the classic Western dialectic of three-dimensional space and linear time was displaced by the integrated concept of spacetime. On that day, modern physics also collided with the traditional Japanese understanding that space and time are interdependent phenomena. This collision speaks to conceptual parallels relating Buddhist thought, modern Japanese philosophy, phenomenology, and the physics of spacetime. The thirteenth-century Zen Buddhist monk Dōgen said that all phenomena are made possible by the universal principle of emptiness and that our existence arises with each moment in what he termed Being-Time, where past, present, and future co-exist. The Japanese philosopher Nishida Kitarō, along with Tanabe Hajime and Watsuji Tetsurō, saw reality as a multi-dimensional field of space-in-time where the individual subject no longer stood apart from the objective world but instead arose dynamically as contingent activities rather than an autonomous thing. The German philosopher Martin Heidegger rejected the rational binary of subject and object in Western thought and grounded our “being” in phenomena that came from their temporal being-in-the-world rather than representing some preexisting objective reality. The physicist Albert Einstein radically rethought the dialectic of three-dimensional space and linear time, used to schematize the physical world in the West since antiquity, and theorized the relativity of spacetime, in which all phenomena occur in space in relation to their place in time. Interwoven, these intellectual threads stripped the bombing of Hiroshima of its historical inevitability. The story of human experience lost its customary sense of going <i>somewhere</i> predetermined and was revealed instead to be an endlessly discrete accumulation of moments that could go <i>anywhere</i> at every transient and directionless moment in time.

Translating Spacetime Intensities of Movie Barcodes

This article proposes a methodology to identify rhetorical energies that form within the diegetic timeline of movies and to translate these to creative sculpting of spacetime designs. In turn, the narrative manipulation of rhetorical spacetime correlates with that of the audience's emotional states. I achieved this by indexing fictional spacetime with movie barcodes to create a visual compression of sequential film frames into one solid image. I also discuss how patterns of spatial and temporal arrangement within the selected film trailer occurs. I utilise the short form movie trailer The Monster (2020) as my case study as it is a work that I co-directed. Essentially, I propose a method to show how temporal designs of a fictional dimension may be sculpted and intensified. For comparative purposes, I discuss a related study on Alejandro G. Iñárritu’s The Revenant (2015). I conclude that the spacetime relationships of the timeline exhibit a propensity to result in dramaturgic tension patterns.

Wind Finslerian Structures: From Zermelo’s Navigation to the Causality of Spacetimes

The notion of wind Finslerian structure Σ \Sigma is developed; this is a generalization of Finsler metrics (and Kropina ones) where the indicatrices at the tangent spaces may not contain the zero vector. In the particular case that these indicatrices are ellipsoids, called here wind Riemannian structures, they admit a double interpretation which provides: (a) a model for classical Zermelo’s navigation problem even when the trajectories of the moving objects (planes, ships) are influenced by strong winds or streams, and (b) a natural description of the causal structure of relativistic spacetimes endowed with a non-vanishing Killing vector field K K (SSTK splittings), in terms of Finslerian elements. These elements can be regarded as conformally invariant Killing initial data on a partial Cauchy hypersurface. The links between both interpretations as well as the possibility to improve the results on one of them using the other viewpoint are stressed. The wind Finslerian structure Σ \Sigma is described in terms of two (conic, pseudo) Finsler metrics, F F and F l F_l , the former with a convex indicatrix and the latter with a concave one. Notions such as balls and geodesics are extended to Σ \Sigma . Among the applications, we obtain the solution of Zermelo’s navigation with arbitrary time-independent wind, metric-type properties for Σ \Sigma (distance-type arrival function, completeness, existence of minimizing, maximizing or closed geodesics), as well as description of spacetime elements (Cauchy developments, black hole horizons) in terms of Finslerian elements in Killing initial data. A general Fermat’s principle of independent interest for arbitrary spacetimes, as well as its applications to SSTK\xspace spacetimes and Zermelo’s navigation, are also provided.

EINSTEINS THEORY OF RELATIVITY AND ORGANIZATIONAL FLEXIBILITY IN DIGITAL TRANSFORMATIONS

The paper will illustrate an analogy of Einsteins Theory of Relativity with the features of organizational flexibility against the backdrop of digital transformations. The relativity of space-time on the structures of organizations in their dynamics has informed the research. Explain how principles of relativity time dilations and space curvatures can be applied in organizational adaptability and responsiveness to give insight on how such flexibility may be achieved in the organisations, especially during digital disruptions. The findings suggest that much like how relativity reset peoples understanding of physics, the flexible approach toward organizational change can reset success in the digital age.

Structural and semantic features of ethno-stereotyping of space-time relations in different linguistic cultures

Structural and semantic features of ethno-stereotyping of space-time relations in different linguistic cultures

Beyond Wilson? Carroll from current deformations

At extreme energies, both low and high, the spacetime symmetries of relativistic quantum field theories (QFTs) are expected to change with Galilean symmetries emerging in the very low energy domain and, as we will argue, Carrollian symmetries appearing at very high energies. The formulation of Wilsonian renormalisation group seems inadequate for handling these changes of the underlying Poincare symmetry of QFTs and it seems unlikely that these drastic changes can be seen within the realms of relativistic QFT. We show that contrary to this expectation, changes in the spacetime algebra occurs at the very edges of parameter space. In particular, we focus on the very high energy sector and show how bilinears of U(1) currents added to a two dimensional (massless) scalar field theory deform the relativistic spacetime conformal algebra to conformal Carroll as the effective coupling of the deformation is dialed to infinity. We demonstrate this using both a symmetric and an antisymmetric current-current deformation for theories with multiple scalar fields. These two operators generate distinct kinds of quantum flows in the coupling space, the symmetric driven by Bogoliubov transformations and the antisymmetric by spectral flows, both leading to Carrollian CFTs at the end of the flow.

Relativistic Consistency of Nonlocal Quantum Correlations.

What guarantees the "peaceful coexistence" of quantum nonlocality and special relativity? The tension arises because entanglement leads to locally inexplicable correlations between distant events that have no absolute temporal order in relativistic spacetime. This paper identifies a relativistic consistency condition that is weaker than Bell locality but stronger than the no-signaling condition meant to exclude superluminal communication. While justifications for the no-signaling condition often rely on anthropocentric arguments, relativistic consistency is simply the requirement that joint outcome distributions for spacelike separated measurements (or measurement-like processes) must be independent of their temporal order. This is necessary to obtain consistent statistical predictions across different Lorentz frames. We first consider ideal quantum measurements, derive the relevant consistency condition on the level of probability distributions, and show that it implies no-signaling (but not vice versa). We then extend the results to general quantum operations and derive corresponding operator conditions. This will allow us to clarify the relationships between relativistic consistency, no-signaling, and local commutativity. We argue that relativistic consistency is the basic physical principle that ensures the compatibility of quantum statistics and relativistic spacetime structure, while no-signaling and local commutativity can be justified on this basis.

Regularity of a double null coordinate system for Kerr–Newman–de Sitter spacetimes

We construct a double null coordinate system (u,v,θ⋆,ϕ⋆) for Kerr–Newman–de Sitter black hole interior spacetimes and prove that the two dimensional spheres given by the intersection of the hypersurfaces u=constant and v=constant are C∞ in Boyer–Lindquist coordinates (including at the “poles"). The null coordinates allow one to immediately extend some results previously proven for Kerr. As an example, we illustrate how Sbierski’s result in (On the initial value problem in general relativity and wave propagation in black-hole spacetimes. Doctoral thesis, 2014. https://doi.org/10.17863/CAM.16140), for the wave equation on the black hole interior, for Reissner–Nordström and Kerr spacetimes, applies to Kerr–Newman–de Sitter spacetimes.

Field trip - Outer Flysch Carpathians, Pieniny Klippen Belt (PKB), and Tatra Mountains

The 36th HKT Workshop (Himalaya-Karakorum- Tibet) is organised by the AGH University of Krakow, Poland. Kraków is situated at the front of the Carpathian orogenic system of the ancient Tethys Ocean and is perfect place for meeting between European-Asian Alpine-Himalayan orogenic belt with long history of the Western and Eastern Tethyan Ocean Realms. The 36th HKT Workshop concerns mainly on this first area and the meeting will be focused on Himalaya-Karakorum-Tibet regions but will be also concentrated (especially during field trip) on comparison between Asian (eastern) and European (western) parts of orogen and geotectonic events based on research of different branches of geology: stratigraphy, paleontology, sedimentology, paleogeography, structural geology, petrology, geochemistry, paleomagnetism, and geophysics. The 36th HKT Workshop is aimed to provide a forum for colleagues from America and Asian/European countries, to present their work and discuss their ideas covering various aspects of the development of the Eurasian Alpine history. We are glad that we can meet personally during the 36th HKT Workshop after the pandemic time, which disrupted our idea of regular, annual meetings. Simultaneously we are under IGCP 710 Project logo (Western Tethys meets Eastern Tethys – geodynamical, paleoceanographical and paleobiogeographical events), and we have now the chance to discuss face to face and go to the field together to touch Carpathian/“Tethyan” rocks for a better understanding of what happened hundreds/decades of millions years ago in our lovely ancient ocean. As you know, through your knowledge and experience, the Tethyan Ocean history, both in its western and eastern parts, is fascinating, but enigmatic from time to time, to say the least. Generally, the geological history of the Tethys Oceanis broadly established. Yet many details are still unknown and many major questions remain, related to geotectonics, palaeogeography, palaeoceanography and palaeobiogeography. Improved understanding of the Mesozoic-Cenozoic ocean/climate history is based on accurate reconstruction of the distribution of continents and ocean basins and on opening and closing of seaways along the Tethys. There is little or no agreement about the number or size of separate basins, nor on their space-time relationships. Moreover, there is no consensus on the number and location of former microcontinents and on their incorporation into the present-day Eurasian-Mountain Belt. Geologists studying individual parts of these belts have been educated within different geological systems and adhere to different geological paradigms. Correlation between Western and Eastern Tethys is difficult, not only because of the large distances involved, but also because they are separated by the area of the huge Himalayan collision within which much of the pre-Paleogene tectonostratigraphic information has been lost. On the one hand, UNESCO forms a special umbrella for the IGCP Projects, and on the other hand, it has been very active in supporting the ideas of “geoparks” and “geotourism” for years. For this reason, we decided to use an international magazine – “Geotourism” – to print the field trip guidebook [“Geotourism”, 2024, 76-77(1-2)]. We hope it will be useful for both Alpine-Himalayan/Tethyan friends and geotourism enthusiasts. Enjoy Kraków during the stationary part of the 36th HKT Workshop and the Polish-Slovak-Czech Carpathians during a 5-day field trip!

Images and bodies of the ñandú (rhea americana) in the celebrationsof the qom people

Based on the ethnography of qom (toba) communities living on the right bank of the middle Bermejo River, in the ArgentineChaco, I address the relationship of this people with the ñandú (Rhea americana), a bird native to South America and closelylinked to the hunting tradition in the Gran Chaco. I argue that beyond the hunting activity, this relationship is inscribed in the Chaco landscape, in the memories, cosmology and celebrations of the qom people. This case is framed by the contemporary anthropological debate on the classic opposition between practices and ethos of domestication and hunting, that I approach from the context of indigenous feasts and their ability to congregate in the same space-time human relations and prominent links with plant and animal species. I conclude that the qom’s proximity to the images and body of ñandú, beyond turning the bird into an object of human hunting or significance, allowed them to understand the way of dealing with transformations configured by the alternation between abundance and scarcity, as extremes that shape the landscape and life in the Chaco.