Temporal Counterpart Research Articles

Topological transport of a classical droplet in a lattice of time

AbstractThouless charge pumps are quantum mechanical devices whose operation relies on topology. They provide the means for transporting quantum matter in space lattices with a single quantum precision. Contrasting space crystals that spontaneously break a continuous spatial translation symmetry and form crystals in space, time crystals have emerged as novel states of matter that organise into time lattices and spontaneously break a discrete time translation symmetry. The utility of Thouless pumps that enable topologically protected quantised transport of electrons and neutral atoms in spatial superlattices leads to the question if corresponding devices exist for time crystals. Here we show that topological pumps can be realised for time solids by transporting droplets of a liquid forward and backward in time lattices and we measure the topological index that characterises such pumping processes. By exploiting a synthetic time dimension, classical time crystals can circumvent the quantum tunnelling that underpins Thouless charge pumps. Our results establish topological pumping through time instead of space and pave the way for applications of time crystals.Key Points Periodically driven fluid droplets can be made to bounce persistently in a gravitational field and may undergo spontaneous time translation symmetry breaking forming classical time crystals. These classical time crystals can be pumped from one time site to another, and this pumping process is characterised by a topological index. Our observations establish a classical temporal counterpart to Thouless pumping of quantum particles in space lattices.

Temporal multilayer structures in discrete physical systems towards arbitrary-dimensional non-Abelian Aharonov-Bohm interferences

Temporal modulation recently draws great attentions in wave manipulations, with which one can introduce the concept of temporal multilayer structure, a temporal counterpart of spatially multilayer configurations. This kind of multilayer structure holds temporal interfaces in the time domain, which provides additional flexibility in temporal operations. Here we take this opportunity and propose to simulate a non-Abelian gauge field with a temporal multilayer structure in the discrete physical system. Two basic temporal operations, i.e., the folding/unfolding operation and the phase shift operation are used to design such a temporal multilayer structure, which hence can support noncommutative operations to realize the non-Abelian Aharonov-Bohm interference in the time domain. A two-/three-dimensional non-Abelian gauge field can be built, which may be further extended to higher dimensions. Our work therefore provides a unique platform enabling generalization of non-Abelian physics to arbitrary dimensions and offers a method for wave manipulations with temporal band engineering.

Finch–Skea dark energy stars with vanishing complexity factor

We make use of the complexity factor formalism for static and self-gravitating objects, recently proposed by L. Herrera (2018), for setting up a relativistic, anisotropic dark energy stellar model satisfying the vanishing complexity condition. The condition serves as an aid in closing the system of field equations for General Relativity. The popular Finch–Skea ansatz is used for the metric component, grr, with the temporal counterpart determined by imposing the vanishing complexity condition. We assess the physical acceptability of our dark energy stellar model according to the standard requirements for static, spherically symmetric compact matter, and we study the associated matter quantities with respect to the dark energy coupling parameter, α. The effect of α on our stellar model has been studied in detail. It is established that our model is regular and stable, and the radial pressure vanishes at the surface boundary as required by selecting a suitable range for α. We find that the coupling parameter influences the baryonic energy density and pressures; however, the pressure anisotropy remains largely unaffected. This is a novel feature of our dark-energy star model, obtained via the vanishing complexity condition. We further demonstrate the robustness of our model in predicting the observed radii of well-known compact objects such as 4U 1820-30, Vela X-1, LMC X-4, PSR J1614-2230, and PSR J1903+0327 by varying a free parameter arising in the Finck–Skea ansatz. Our findings show that our solution predicts masses beyond the standard general relativity limit of 2.0 M⊙ for neutron stars. The prediction of compact objects with masses in the range of 2.5 M⊙ within our solution-generating framework augers well for the observation of gravitational waves arising in binary mergers.

Atmospheric Climatologies Over Isfjorden, Svalbard

AbstractThe Isfjorden region at the west coast of Spitsbergen is the most easily accessible area in the Svalbard Archipelago, making it a perfect outdoor laboratory for Arctic research. Due to its location in the high Arctic together with its complex terrain, the climatic conditions vary substantially both in time and space. Based on a new high‐resolution reanalysis, we present climatologies of five major atmospheric variables over the Isfjorden region during 2011–2021 with special focus on local effects. For example, we find that topographic channeling effects often lead to differences in near‐surface wind speeds of several m s−1 over small horizontal distances. During winter, the fjord acts as a heat and moisture island, ultimately impacting the adjacent low‐elevation land areas. These land–sea gradients reverse during summer. High mountain areas surrounding the fjord experience substantially different climatic conditions, with for example, seasonal precipitation doubling from sea level to approximately 700 m. The spatial variability over the Isfjorden region is in general found to be smaller than its temporal counterpart but larger than the diurnal cycle. Besides these findings, this study furthermore demonstrates the importance of high‐resolution regional atmospheric reanalyses compared to global products for the characterization of the local micro‐climate over Arctic fjords and the interaction with surrounding land areas.

Quantized momentum eigenstates and thermodynamic properties of the Feinberg–Horodecki equation for the time-dependent Wei-Hua oscillator

In this study, we obtained exact solutions of the Feinberg–Horodecki equation for the time-dependent Wei-Hua potential, which is constructed by the temporal counterpart of the spatial form of this potential. We obtained the quantized momentum eigenvalues and the corresponding wave functions. We obtained the partition function for the system and studied other thermodynamic properties that include vibrational mean momentum ( U), vibrational specific heat capacity ( C), vibrational entropy ( s), and vibrational free momentum ( F) as a signature in the momentum space.

A stabilized formulation for the solution of the incompressible unsteady Stokes equations in the frequency domain

A stabilized finite element method is introduced for the simulation of time-periodic creeping flows. This new technique, which is formulated in the frequency rather than time domain, strictly uses real arithmetics and permits the use of similar interpolation functions for pressure and velocity for ease of implementation. It involves the addition of the Laplacian of pressure to the continuity equation with a complex-valued stabilization parameter that is derived systematically from the momentum equation. The numerical experiments show the excellent accuracy and robustness of the proposed method in simulating flows in complicated and canonical geometries for a wide range of conditions. The present method is mass conservative up to the tolerance of the underlying linear solver. It significantly outperforms its temporal counterpart, namely the standard pressure stabilized Petrov-Galerkin method, by lowering the cost and solution turnover time of the simulated cases by several orders of magnitude.

Short-Pulsed Metamaterials.

We study a class of temporal metamaterials characterized by time-varying dielectric permittivity waveforms of duration much smaller than the characteristic wave-dynamical timescale. In the analogy between spatial and temporal metamaterials, such a short-pulsed regime can be viewed as the temporal counterpart of metasurfaces. We introduce a general and compact analytical formalism for modeling the interaction of a short-pulsed metamaterial with an electromagnetic wave packet. Specifically, we elucidate the role of local and nonlocal effects, as well as the time-reversal symmetry breaking, and we show how they can be harnessed to perform elementary analog computing, such as first and second derivatives. Our theory validated against full-wave numerical simulations suggests a novel route for manipulating electromagnetic waves without relying on long, periodic temporal modulations. Just as metasurfaces have played a pivotal role in the technological viability and practical applicability of conventional (spatial) metamaterials, short-pulsed metamaterials may catalyze the development of temporal and space-time metamaterials.

Modelling control strategies against classical swine fever: Influence of traders and markets using static and temporal networks in Ecuador

Pig farming in Ecuador represents an important economic and cultural sector, challenged by classical swine fever (CSF). Recently, the National Veterinary Service (NVS), has dedicated its efforts to control the disease by implementing pig identification, mandatory vaccination against CSF and movement control. Our objective was to characterise pig premises according to risk criteria, to model the effect of movement restriction strategies and to consider the temporal evolution of the network. Social network analysis (SNA), SIRS (susceptible, infected, recovered, susceptible) network modelling and temporal analysis were used. The network contained 751,003 shipments and 6 million pigs from 2017 to 2019. Participating premises consisted of 144,118 backyard farms, 138 industrial farms, 21,337 traders and 51 markets. The 10 most influential markets, in the Andean highlands, received between 500 and 4600 pigs each week. The 10 most influential traders made about 3 shipments with 17 pigs per week. Simulations without control strategy resulted in an average CSF prevalence of 14.4 %; targeted movement restriction reduced the prevalence to 7.2 %, while with random movement restriction it was 13 %. Targeting the top 10 national traders and markets and one of the high-risk premises in every parish was one of the best strategies with the surveillance infrastructure available, highlighting its major influence and epidemiological importance in the network. When comparing the static network with its temporal counterpart, causal fidelity (c = 0.62) showed a 38 % overestimation in the number of transmission paths, also traversing the network required 4.39 steps, lasting approximately 233 days. In conclusion, NVS surveillance strategies could be more efficient by targeting the most at-risk premises, and in particular, taking into account the temporal information would make the risk assessment much more precise. This information could contribute to implement risk-based surveillance reducing the time to eradicate CSF and other infectious animal diseases.

Grammaticalisation of ʔelħi:n in Haili Arabic- From Propositional Item to Discourse Particle: Split CP Investigation

This paper explores the linguistic properties of a discourse variant of the temporal adverb ʔelħi:n, used in Haili Dialect of Najdi Arabic (HA). Maintaining the characteristic of co-occurring clause-initially, and examining lexical/discoursal articulated structures, ʔelħi:n has developed a conventionalized discourse use, turning its morphology into a discourse particle that expresses a degree of speaker’s attitude. ʔelħi:n has undergone a process of grammaticalisation, with morphosyntactic consequence: changing its phrasal status to a head one. Evidence supporting this direction derives from intervention effects (Rizzi, 2006)- ʔelħi:n inhabits movement of head-items in syntax. The immediate consequence of this morphosyntactic change has direct impact on the syntax of ʔelħi:n: occurring clause-initially and its phonology: being unable to bear high tone, unlike its temporal adverb counterpart. Implementing cartographic mechanisms, Rizzi’s (1997) Split CP System, and holding to observations that inherently focused material wh-phrase leɪʃ ‘why’ merges in a position c-commanded by ʔelħi:n, it is established that the discourse instance of ʔelħi:n first merges at a discourse head, instantiating a discourse projection, PrtP, whence it semantically wide-scopes the propositional-TP. Constituents preceding ʔelħi:n are then argued to move and remerge at some Spec of a discourse phrase, C-TopP (Frascarelli & Hinterhölzl, 2007). Mapping the CP-layer of HA, the PrtP headed by ʔelħi:n maintains a rigid order in syntax with respect to CP-items, which makes a possible, initial mapping to the left periphery of HA, calling for scrutiny of more structure.

The future

In the 1990s and early 2000s, Rabinow turned to the study of emergent assemblages, which are rooted in the recent past and possess an uncertain future. The turn to assemblages therefore brings a distinctive temporality into view. Attending to this temporality, this essay examines Rabinow’s interest in “the future” by proposing two observations. First, it argues that Rabinow’s handling of the future is shaped by his thorough rejection of nostalgia. Second, it suggests that Rabinow’s emphasis on the “near” future is a temporal counterpart to his more general interest in the semi-local and near-at-hand as ways of delimiting the scale of objects of inquiry. Together, these qualities give Rabinow’s scholarship a provisional openness to things yet to come, and the sensitivity to grasp the filaments of a possible future.

Right temporal variant frontotemporal dementia is pathologically heterogeneous: a case-series and a systematic review

Although the right temporal variant frontotemporal dementia (rtvFTD) is characterised by distinct clinical and radiological features, its underlying histopathology remains elusive. Being considered a right-sided variant of semantic variant primary progressive aphasia (svPPA), TDP-43 type C pathology has been linked to the syndrome, but this has not been studied in detail in large cohorts. In this case report and systematic review, we report the autopsy results of five subjects diagnosed with rtvFTD from our cohort and 44 single rtvFTD subjects from the literature. Macroscopic pathological evaluation of the combined results revealed that rtvFTD demonstrated either a frontotemporal or temporal evolution, even if the degeneration started in the right temporal lobe initially. FTLD-TDP type C was the most common underlying pathology in rtvFTD, however, in 64% of rtvFTD, other underlying pathologies than FTLD-TDP type C were present, such as Tau-MAPT and FTLD-TDP type A and B. Additionally, accompanying motor neuron or corticospinal tract degeneration was observed in 28% of rtvFTD patients. Our results show that in contrast to the general assumption, rtvFTD might not be a pure FTLD-TDP type C disorder, unlike its left temporal counterpart svPPA. Large sample size pathological studies are warranted to understand the diverse pathologies of the right and left temporal variants of frontotemporal dementia.

Grounding Personal Persistence

AbstractModal counterpart theory identifies a thing’spossibly being Fwith its having a counterpart that isFat another possible world; temporal counterpart theory identifies a thing’shaving been Forgoing to be F, with its having a counterpart that isFat another time.Benovsky, J. 2015. “Alethic Modalities, Temporal Modalities, and Representation.”Kriterion: Journal of Philosophy29: 18–34 in this journal endorses modal counterpart theory but holds that temporal counterpart theory is untenable because it does not license the ascription of the intuitively correct temporal properties to ordinary objects, and hence that we should understand ordinary objects, including persons, as transtemporal ‘worms’. I argue that the worm theory is problematic when it comes to accounting for what matters in survival and that temporal counterpart theory provides a plausible account of personal persistence.

A case of peripapillary pachychoroid syndrome treated with anti-vascular endothelial growth factor injections

Peripapillary pachychoroid syndrome (PPS) is a novel variant in the pachychoroid disease spectrum in which pachychoroid features are more prominent around the optic nerve head and are associated with intraretinal and/or subretinal fluid. The choroidal thickness in PPS is characterized by its atypical distribution with nasal macular choroid being thicker than the temporal counterpart. There are a few case reports of PPS in the literature that describe the morphological features of PPS but the management protocols are yet to be established. We hereby describe the clinical course of a 54-year-old gentleman who came to us with complaints of a gradual decrease in vision. On basis of multimodal imaging, a diagnosis of PPS was made. Since the patient was symptomatic, he was treated with intravitreal aflibercept which showed a favorable anatomical and functional outcome.

Counterpart Theories: The Argument from Concern

AbstractModal counterpart theory identifies a thing’spossibly being Fwith its having a counterpart that isFat another possible world; temporal counterpart theory, thestage view, according to which people and other ordinary objects are instantaneous stages, identifies a thing’shaving been Forgoing to be F, with its having a counterpart that isFat another time. Both counterpart theories invite what has been called ‘the argument from concern’ (Rosen, G. 1990. “Modal Fictionalism.” Mind 99 (395): 327–54). Why should I be concerned about my counterparts at other possible worlds or other times? I care about how things might have gone forme—not how they go for other people at other possible worlds; I care aboutmyprospects—not the way go for other people at other times. Jiri Benovsky has argued that while modal counterpart theory can be defended against this style of argument, temporal counterpart theory cannot (Benovsky, J. 2015. “Alethic Modalities, Temporal Modalities, and Representation.” Kriterion: Journal of Philosophy 29: 18–34). I argue that temporal counterpart theory, like modal counterpart theory, resists the argument from concern.

Modelling Control Strategies Against Classical Swine Fever: Influence of Traders and Markets Using Static and Temporal Networks in Ecuador

Pig farming in Ecuador represents an important economic and cultural sector. Recently, the National Veterinary Service has implemented individual identification of pigs, stricter movement control and mandatory vaccination against classical swine fever (CSF), which has been prevalent since 1940. The information registered since 2017 seems valuable for applying modelling techniques assessing the risk of dissemination of animal diseases and test control strategies. Social network analysis (SNA) was used to characterise the premises into risk categories, looking for better targeting surveillance activities and identifying higher risk targets. Network modelling was used to test the disease spread and control strategies over the network, using a Susceptible, Infected, Recovered, Susceptible SIRS model to compare a target selection of high-risk nodes against the current traditional surveillance. Finally, temporal network analysis revealed general trends in the network's evolution. The network contained 751,003 movements with 6 million pigs, excluding movements to slaughterhouses. A total of 165,593 premises were involved in network movements (144,118 farms, 138 industrials, 21,337 traders and 51 markets). On an annual average, 75% of the premises (124,976) received or sent up to one movement with an annual average of 1.5 pigs. In contrast, 0.01% of the premises (166) made up to 1,372 movements, with an annual average of 11,607 pigs. Simulations on the network resulted in the dissemination of CSF, reaching a mean prevalence of 29.93% without a control strategy. The random selection strategy reduced the prevalence to 24.4%, while target selection by risk reduced to 3.3%. When comparing the static representation of the network with the temporal counterpart, causal fidelity (c = 0.62) showed an overestimation of 38% in the number of transmission paths, even though it took an average of 4.39 steps to cross the network, these steps took approximately 233 days. The characterisation of the premises acting on the Ecuadorian network, based on risk emphasis, and the application of network modelling techniques can support the redesign of the surveillance system. Minor changes could enable the implementation of risk-based surveillance, targeting specifically the nodes at higher risk and considering special attention to markets and traders.

Non-stationary pulses with complex-valued temporal degree of coherence

It is shown that fine phase structuring of the temporal degree of coherence of a non-stationary pulse source leads to breaking its average arrival time symmetry on propagation in a linear dispersive medium. We employ the temporal counterpart of a recently proposed sliding function technique ((2018) Opt. Lett. 43 4727) for obtaining several models for the bona fide complex temporal degree of coherence of Schell-model non-stationary pulse trains and examine their evolution in fibers with and without a chirper. In particular we have examined linear, signum, cubic and trochoid phase models of the temporal degree of coherence. We also propose a simple method for experimental realization of the new pulsed sources and offer computer simulations confirming its viability.

An anamorphic time-lens-based optical cryptosystem for protection of time-varying signals

The similarity between in-plane directions of spatial optics and overlapped time ranges of temporal optics is introduced as a new rule of the space–time duality. Applying this rule, an optical dual random phase encoding (DRPE) cryptosystem in the temporal anamorphic fractional Fourier transform (TAFrFT) domain is proposed for physical-level protection of time-varying signals. The structure of a TAFrFT system is an anamorphic time lens (ATL) sandwiched by two identical dispersion elements. The additional key provided by a TAFrFT system is only related to phase profile of the involved ATL, leading to a dispersion-independent manner of key updating as well as an enlarged key space (KS) in comparison with the conventional temporal FrFT and Fresnel transform system. This manner of key updating has potential as a one-time key strategy to evade the intrinsic linearity and symmetry weakness of DRPE-like temporal cryptosystems, due to the updating speed being comparable to the frame rate of plaintext signals. As the temporal counterpart of a spatial optical device composed of cylindrical lenses along different directions, an ATL is designed as an equal-spaced array of time lenses with unipolar phase, constant extension, and varying phase height. Implemented by an arbitrary waveform generator (AWG)-driven electro-optic phase modulator (EOPM), the time interval of adjacent time lenses, extension of each time lens, and the standard phase height are optimally designed as functions of the AWG bandwidth B M and the EOPM damage phase threshold . By numerical simulations, a 16-slot input optical Gaussian pulse sequence with half pulse width of 10 ps and frame length of 2000 ps is encrypted with a KS near provided by ATLs at parameters GHz and radians under the state of the art, enough for resistance to brute-force attacks.

Wood Anomalies and Surface-Wave Excitation with a Time Grating.

In order to confine waves beyond the diffraction limit, advances in fabrication techniques have enabled subwavelength structuring of matter, achieving near-field control of light and other types of waves. The price is often expensive fabrication needs and the irreversibility of device functionality, as well as the introduction of impurities, a major contributor to losses. In this Letter, we propose temporal inhomogeneities, such as a periodic drive in the electromagnetic properties of a surface which supports guided modes, as an alternative route for the coupling of propagating waves to evanescent modes across the light line, thus circumventing the need for subwavelength fabrication, and achieving the temporal counterpart of the classical Wood anomaly. We show analytically and numerically how this concept is valid for any material platform and at any frequency, and propose and model a realistic experiment in graphene to couple terahertz radiation to plasmons with unit efficiency, demonstrating that time modulation of material properties could be a tunable, lower-loss and fast-switchable alternative to the subwavelength structuring of matter for near-field wave control.

Concurrent static and dynamic dissimilarity analytics for fine-scale evaluation of process data distributions

Dissimilarity algorithm has been widely used for timely identifying changes of data distribution in fine scale while many distance-based monitored indexes still stay inside the normal region. However, it ignores the information of temporal distribution, thus fails to monitor operating conditions and process dynamics separately. In order to detect incipient faults sensitively and also provide more benefiting process comprehension, concurrent static and dynamic dissimilarity analytics based on slow feature analysis technique (CSDDISSIM) is developed in this work. The distributions of process status and dynamics are evaluated in fine scale. First, static features and their temporal counterpart are extracted, in which slow and fast varying information is separated for distribution evaluation. Then the changes of both static and dynamic distributions are checked and the monitoring policy is developed to distinguish different statues, including normal, static deviation, dynamic abnormality, and concurrent deviations. In this way, the industrial process status can be captured with a beneficial interpretation. The practical utility and efficacy of the proposed method are illustrated in the application to a real thermal power plant process.

Unpacking the meaning of the DM now through its Polish translation equivalents

Depending on context, the English lexeme now can be used either as a time adverb or a discourse marker (DM). Unlike its temporal counterpart, the discursive now does not lend itself to a straightforward translation into Polish, representing instead a complex, one-to-many kind of relationship between the original and the target language. Based on the assumption that cross-linguistic research making use of translation data may be highly revealing about semantically opaque expressions, such as DMs, the study aims to gain a deeper insight into the nature of now by looking at its Polish equivalents from the perspective of their potential to bring to the surface and elucidate the functions that the marker serves in various contexts. The image of the DM now which emerges from the study is that of a contextually richly nuanced expression, fulfilling numerous discourse-structuring and intensifying functions. In its structural role, now proves capable of marking a number of different relations between discourse segments, such as contrast, result, return, explanation or elaboration. As an intensifying device, the DM can be more explicitly emotive (expressing, for instance, irritation or disbelief), emphatic or conative in nature. In more general terms, the paper shows how a translation-based study may inform pragmatic research.