Unitary Approach Research Articles

Envy: definitions, approaches and implications

ABSTRACT While envy is a complex emotion to date, voluminous work has been done on the subject; however, no study has been conducted to resolve the debate on key envy-related concepts such as its definition, approaches and dimensions. Having its roots back in 1712, the explorations about envy have radically increased, especially in the twenty-first century, resulting in myriad theoretical and empirical developments. This paper takes this initiative by reviewing 76 systematically selected articles published in the services context in 41 journals to summarize the evolution of envy while addressing key research questions (what is envy, its nature, antecedents, and outcomes). Based on the review, this study tries to resolve the debate regarding two key elements of envy: its definition and approaches, i.e. unitary and dual. Following the unitary approach, we reported the most practical definition of envy and found that the view of self generates positive outcomes, and the view of others generates negative outcomes of envy.

P_{cc}^N states in a unitarized coupled-channel approach

Starting from an effective Lagrangian with heavy quark spin symmetry embedded, the coupled-channel dynamics of the doubly charmed systems D^{(*)} Sigma _c^{(*)} is investigated. The potential underlying our investigation includes t-channel pseudoscalar and vector meson exchanges. A series of S-wave bound states with isospin I=1/2 is found by applying the first iterated solution of the N/D method: one state with binding energy 23 MeV in the 5/2^-D^*Sigma _c^* channel, three states with binding energy 26, 30 and 7 MeV (relative to the thresholds from low to high, respectively) in the 3/2^-DSigma _c^*-D^*Sigma _c-D^*Sigma _c^* system and three states with binding energy 32, 8 and 16 MeV in the 1/2^-DSigma _c-D^*Sigma _c-D^*Sigma _c^* system. Those P_{cc}^N states serve as the open-charm partners of the hidden charm pentaquarks P_{psi }^N observed by the LHCb Collaboration.

Role of the scalar in the process * *Supported by the National Natural Science Foundation of China (12192263), the Natural Science Foundation of Henan Province, China (222300420554), the Project of Youth Backbone Teachers of Colleges and Universities of Henan Province, China (2020GGJS017), the Youth Talent Support Project of Henan Province, China (2021HYTP002), and the Open Project of Guangxi Key Laboratory

Based on BESIII measurements of the reaction , we investigate this process by considering the S-wave pseudoscalar-pseudoscalar interaction within the unitary chiral approach and the contributions from the intermediate resonances and . Our calculation can reasonably reproduce the experimental data, and our results imply that , which is dynamically generated from the S-wave pseudoscalar-pseudoscalar interaction, plays an important role in this process, and the contributions from the intermediate resonances and are also necessary. More precise measurements of this process in future can shed light on the nature of and .

Post-earthquake reconstruction of residential buildings in historical centers: damage indices of structural aggregates

The post-earthquake reconstruction process of historical centers discloses several issues due to the complexity of the built heritage, typically consisting of Building Aggregates (BA). These are characterized by structures deriving from progressive volume increases that, due to partially effective connections, can interact under seismic actions. Therefore, the repair and reconstruction work after seismic event, the conservation of the architectural values and the improvement of seismic and energy performances must rely on a deeper knowledge of the BA seismic behavior and on an unitary design approach. This paper presents an analysis of the damage caused by the 2009 earthquake to the buildings of the historical centers in the Abruzzo Region, with particular interest to the BA considered as a single structural block. A new perspective of the damage on structural and non-structural components, detected by means of the AeDES form, a first level survey form for post-earthquake damage and usability assessment, is proposed. The data related to the building damage are converted into an equivalent global building damage associated to the BA using conversion metrics found in the literature. Finally, some considerations are provided to evaluate the global building damage, necessary to the development of a comprehensive damage state.

Complex interactions confound any unitary approach to social phenomena, not just biological ones.

Although Burt clearly explains how modern genomic techniques work, and describes their limitations, her conclusion that they are therefore not valuable additions to understanding social outcomes is unwarranted. Understanding the causes of complex social outcomes depends on understanding how social, individual, and genetic factors complexly interact with each other. None can be understood without reference to the others.

Distribution of controlled unitary quantum gates towards factoring large numbers on today’s small-register devices

Factoring a 2048-bit number using Shor's algorithm, when accounting for error correction, reportedly requires 400,000 qubits. However, it is well known that there is yet much time before we will have this many qubits in the same local system. This is why we propose a protocol for distributed quantum computation applicable to small register devices, specifically for the distribution of controlled unitary gates, the key element in the construction of every quantum computation algorithm. We leverage quantum sharing of partial results to obtain a parallel processing scheme, allowing for the first time the quantum distribution of very large gates with thousands of inputs using only small register devices with tens of qubits. In this way, we improve all previous controlled unitary gate distribution approaches, obtaining surprising results. The impact is quantified for recent milestone hardware realizations of quantum processors.

Role of meson interactions in the Ds+→π+π+π−η decay

We perform a theoretical study of the $D_s^{+}\to \pi^{+}\pi^{+}\pi^{-}\eta$ decay. We look first at the basic $D_s^{+}$ decay at the quark level from external and internal emission. Then hadronize a pair or two pairs of $q\bar{q}$ states to have mesons at the end. Posteriorly the pairs of mesons are allowed to undergo final state interaction, by means of which the $a_0(980)$, $f_0(980)$, $a_1(1260)$, and $b_1(1235)$ resonances are dynamically generated. The $G$-parity is used as a filter of the possible channels, and from those with negative $G$-parity only the ones that can lead to $\pi^{+}\pi^{+}\pi^{-}\eta$ at the final state are kept. Using transition amplitudes from the chiral unitary approach that generates these resonances, and a few free parameters, we obtain a fair reproduction of the six mass distributions reported in BESIII experiment.

Capabilities and limits of the unitary coupled-cluster approach with generalized two-body cluster operators.

Unitary cluster expansions of the electronic wavefunction have recently gained much interest because of their use in conjunction with quantum algorithms. In this contribution, we investigate some aspects of an ansatz, using generalized two-body excitation operators, which have been considered in some recent studies on quantum algorithms for quantum chemistry. Our numerical results show that, in particular, two-body operators with effective particle-hole excitation level of one in connection with the usual particle-hole double excitation operators lead to a very accurate, yet compact representation of the wavefunction. Generalized two-body operators with effective excitation rank zero have a considerably less pronounced effect. We compare with standard and unitary coupled-cluster expansions and show that the above mentioned approach matches or even surpasses the accuracy of expansions with three-body particle-hole excitations, in particular at the onset of strong correlation. A downside of the approach is that it is rather difficult to rigorously converge it to its variational minimum.

Vandermonde-Based Unitary Precoding Method for Integer-Forcing Design

An integer-forcing linear receiver has significantly better performance than conditional receivers for slow-fading channels because it directly recovers an integer linear combination of signals instead of decoding all signals. The performance in terms of achievable rate, outage probability, and error rate can be improved with a unitary matrix precoder imposed at each channel realization. In this paper, a new special unitary matrix precoding approach is proposed to reduce the computational complexity. Different from the parameterization technique with many parameters, the new method constructs a unitary Vandermonde matrix with only a single parameter. The optimal Vandermonde matrix is determined on the basis of the shortest vector of a lattice generated by the precoding matrix in which the single parameter is searched. Therefore, its complexity is reduced to a polynomial time, whereas the traditional unitary precoder has exponential complexity. Simulation results show that the proposed scheme can achieve the performance similar to the benchmark schemes but with much lower complexity. The scheme offers a good trade-off between performance and complexity.

Roles of a0(980) , Λ(1670) , and Σ(1385) in the Λc+→ηΛπ+ decay

Recently, the Belle Collaboration has measured the ${\mathrm{\ensuremath{\Lambda}}}_{c}^{+}\ensuremath{\rightarrow}\ensuremath{\eta}\mathrm{\ensuremath{\Lambda}}{\ensuremath{\pi}}^{+}$ decay and reported the $\ensuremath{\eta}\mathrm{\ensuremath{\Lambda}}$ and $\mathrm{\ensuremath{\Lambda}}{\ensuremath{\pi}}^{+}$ invariant mass distributions, which show the clear signals of the resonances $\mathrm{\ensuremath{\Lambda}}(1670)$ and $\mathrm{\ensuremath{\Sigma}}(1385)$, respectively. Based on our previous works [Eur. Phys. J. C 76, 496 (2016) and Phys. Rev. D 95, 074024 (2017)], we reanalyze this process by considering the $S$-wave $\ensuremath{\eta}\mathrm{\ensuremath{\Lambda}}$ and $\ensuremath{\eta}{\ensuremath{\pi}}^{+}$ final state interactions within the chiral unitary approach, which dynamically generate the $\mathrm{\ensuremath{\Lambda}}(1670)$ and ${a}_{0}(980)$, respectively. Our results are in agreement with the Belle measurements of the $\ensuremath{\eta}\mathrm{\ensuremath{\Lambda}}$ and ${\ensuremath{\pi}}^{+}\mathrm{\ensuremath{\Lambda}}$ invariant mass distributions. In addition, the ${\ensuremath{\pi}}^{+}\ensuremath{\eta}$ invariant mass distribution is also calculated and a cusp structure of ${a}_{0}(980)$ is clearly shown around the $K\overline{K}$ mass threshold.

Faddeev fixed-center approximation to the Dbar{D}K system and the hidden charm K_{cbar{c}}(4180) state

We perform a theoretical study on the Dbar{D}K three body system, using the fixed center approximation to the Faddeev equations, considering the interaction between D and K, D and bar{D} from the chiral unitary approach. We assume the scattering of K meson on a clusterized system Dbar{D}, where a scalar meson X(3720) could be formed. Thanks to the strong DK interaction, where the scalar D^*_{s0}(2317) meson is dynamically generated, a resonance structure shows up in the modulus squared of the three body K-(Dbar{D})_{X(3720)} scattering amplitude and supports that a Dbar{D}K bound state can be formed. The result is in agreement with previous theoretical studies, which claim a new excited hidden charm K meson, K_{cbar{c}}(4180) with quantum numbers I(J^P) = frac{1}{2}(0^-) and mass about 4180 MeV. It is expected that these theoretical results motivate its search in experimental measurements.

An Incursion into Actuality: Addressing the Precautionary Principle in the Context of the Circular Economy

The circular economy (CE) and the precautionary principle (PP) are two current and contemporary notions; however, they are far from being sufficiently explored and exploited, since each is considered questionable in part. Sensing a niche at the conceptual and scientific research level regarding the unitary approaches of the CE and PP, we carried out a parallel analysis of the notions of the CE and PP with the aim of evaluating and identifying areas of manifestation and interaction. By superimposing the two concepts in feasible situations and analyzing one notion in connection with the other, within the presented examples, the particularities of the CE–PP manifestation were obtained, as well as the consequences of the non-uniform application of the mentioned factors. Also, the results of the research support the hypothesis of the compatibility between the CE and PP in certain cases and attest to the usefulness of the PP in fulfilling the wishes of the CE. Despite the generally parallel existence of the CE and PP, these concepts are not mutually exclusive; the CE cannot be manifested discretionarily but only with certain standards and limits including the requirements imposed by the PP. The results obtained, combined with the provision of an analysis of the current state of knowledge in the field, make the proposed study a useful material for future in-depth research activities on the topic.

Spin-density calculation via the graphical unitary group approach

In this work we discuss the calculation of the spin-density matrix from fundamental spin principles as implemented in the COLUMBUS Program System employing the graphical unitary group approach (GUGA). First, a general equation for the spin-density matrix is derived in terms of the one-and two-particle reduced density matrices, quantities that are spin-independent and readily available within the GUGA formalism. Next, the evaluation of this equation using the Shavitt loop values is discussed. Finally, the spatially resolved counterpart of the spin-density matrix, the spin distribution, is calculated for the phenalenyl radical and structures produced by heteroatoms with mono- and di-substitutions. The physical meaning of the spin-density along with its computational description using various methods is discussed putting special emphasis on negative contributions to the spin-density and their quantification via a spin-promotion index.

Is Pcs(4459) one state or two?

The LHCb collaboration reported recently a charm-strange pentaquark state Pcs(4459) found in the J/ψΛ invariant mass distribution. Using a coupled channel unitary approach combined with the local hidden gauge formalism, we investigate the D¯(∗)Ξ (∗,0) c interactions, together with the J/ψΛ and other coupled channels, with the constraints of the heavy quark spin symmetry. We dynamically reproduce the Pcs(4459) state in the coupled channel interactions, which is a degenerate state of D¯ ∗Ξc and analogous to the Pc(4450) state before. Furthermore, we make more predictions for future experiments.

The Culture-Centered Development Potential of Communities in Făgăraș Land (Romania)

Făgăraș Land (Romania) is a very old administrative formation with its own identity, preserved from the beginning of the Middle Ages. The mapping of the intangible cultural heritage (ICH) highlighted the groups of caroling lads as the main strategic heritage resource, but also the existence of many other ICH resources that can be exploited towards the sustainable development of the area. These include local soups, an ICH gastronomic resource that can help build the area’s tourism brand. All resources, together with the peculiarities of the local medieval history, the memory of the anti-communist resistance in the Făgăraș Mountains and the religious pilgrimage to the local Orthodox monasteries, support the configuration of Făgăraș Land as a multidimensional associative cultural landscape. The content analysis of the information on ICH available on the official websites of the administrative territorial units (ATUs), correlated with the data from the interviews with local leaders, highlighted the types of local narratives regarding the capitalization of cultural resources and the openness to culture-centered community-based development, namely glocal, dynamic local and static local visions. The unitary and integrated approach of tourist resources, tourism social entrepreneurship, support from the local commons and a better management of the local cultural potential are ways to capitalize on belonging to the Făgăraș Land cultural landscape, towards sustainable community development of the area.

Combined unitary and symmetric group approach applied to low-dimensional Heisenberg spin systems

A novel combined unitary and symmetric group approach is used to study the spin-$\frac{1}{2}$ Heisenberg model and related Fermionic systems in a total spin-adapted representation, using a linearly-parameterised Ansatz for the many-body wave function. We show that a more compact ground-state wave function representation---indicated by a larger leading ground-state coefficient---is obtained when combining the symmetric group ${\mathcal{S}}_{n}$, in the form of permutations of the underlying lattice site ordering, with the cumulative spin coupling based on the unitary group $\mathrm{U}(n)$. In one-dimensional systems the observed compression of the wave function is reminiscent of block-spin renormalization group approaches, and allows us to study larger lattices (here taken up to 80 sites) with the spin-adapted full configuration interaction quantum Monte Carlo method, which benefits from the sparsity of the Hamiltonian matrix and the corresponding sampled eigenstates that emerge from the reordering. We find that in an optimal lattice ordering the configuration state function with highest weight already captures with high accuracy the spin-spin correlation function of the exact ground-state wave function. This feature is found for more general lattice models, such as the Hubbard model, and ab initio quantum chemical models, exemplified by one-dimensional hydrogen chains. We also provide numerical evidence that the optimal lattice ordering for the unitary group approach is not generally equivalent to the optimal ordering obtained for methods based on matrix-product states, such as the density-matrix renormalization group approach.

Coupled Cluster Downfolding Theory: towards universal many-body algorithms for dimensionality reduction of composite quantum systems in chemistry and materials science

The recently introduced coupled cluster (CC) downfolding techniques for reducing the dimensionality of quantum many-body problems recast the CC formalism in the form of the renormalization procedure allowing, for the construction of effective (or downfolded) Hamiltonians in small-dimensionality sub-space, usually identified with the so-called active space, of the entire Hilbert space. The resulting downfolded Hamiltonians integrate out the external (out-of-active-space) Fermionic degrees of freedom from the internal (in-the-active-space) parameters of the wave function, which can be determined as components of the eigenvectors of the downfolded Hamiltonians in the active space. This paper will discuss the extension of non-Hermitian (associated with standard CC formulations) and Hermitian (associated with the unitary CC approaches) downfolding formulations to composite quantum systems commonly encountered in materials science and chemistry. The non-Hermitian formulation can provide a platform for developing local CC approaches, while the Hermitian one can serve as an ideal foundation for developing various quantum computing applications based on the limited quantum resources. We also discuss the algorithm for extracting the semi-analytical form of the inter-electron interactions in the active spaces.

Non-invasive surface profile measurement using a unitary transformation subspace approach in digital holography

Fast and accurate measurements of surface profiles is of vital importance in the field of non-destructive material testing. In the article, we propose the application of a robust phase retrieval method in digital holographic microscopy for nanoscale surface profile measurement. The proposed method is based on a parameter estimation strategy using a unitary transformation procedure applied over a windowed region of the numerically reconstructed wavefield signal. The proposed method is suitable for phase extraction even in the presence of noise and non-uniform amplitude variations. The applicability of the proposed method is demonstrated using both simulation and experimental results.

Convergent and Divergent Legal Trends in Addressing the CORONAVIRUS Pandemic at the EU Level

The greatest humanitarian crisis of the 21st century, triggered by the pandemic emergence and spread of the Covid-19 coronavirus, has caused all European Union States to identify and apply rapid solutions to limit and stop this humanitarian disaster. The ways approached by each Member State in achieving this desideratum were different depending on the potential of assistance and endowment of the hospitals but also on the legal and legislative measures applied. The different percentages of the level of vaccination of the population that vary from state to state show how important is the unitary approach of information measures, strategic organization but also the convergent legislative correlation at the European Union level in stopping this scourge. The percentage of vaccination has proved to be closely linked to saving lives, a conclusion which leads to the need to address a convergent strategy across EU Member States on the measures needed to achieve the highest possible percentage of vaccination at the level of all EU Member States to stop this virus and return to normality.

Scalar resonances in the final state interactions of the decays D0→π0π0π0,π0π0η,π0ηη

We investigate the scalar resonances in the processes of $D^{0} \rightarrow \pi^{0}\pi^{0}\pi^{0}, \pi^{0}\pi^{0}\eta, \pi^{0}\eta\eta$ decays based on the chiral unitary approach for the final state interaction. We start from singly Cabibbo-suppressed production diagrams which provide a primary quark pair to hadronize two pseudoscalar mesons in $D^{0}$ decays. The resonances $f_{0}(500)$, $f_{0}(980)$ and $a_{0}(980)$ are dynamically produced from the final state interactions of the meson pairs. In our results, the experimental data for the $\pi^{0}\eta$ invariant mass spectrum of the $D^{0} \rightarrow \pi^{0}\eta\eta$ decay can be described well. We also make the predictions for the $\pi^{0}\pi^{0}$ invariant mass spectrum of the $D^{0} \rightarrow \pi^{0}\pi^{0}\pi^{0}$, where the $f_{0}(980)$ can be found, and for the $\pi^{0}\pi^{0}$, $\pi^{0}\eta$ invariant mass spectrum of the $D^{0} \rightarrow \pi^{0}\pi^{0}\eta$, where the $f_{0}(500)$, $f_{0}(980)$ and $a_{0}(980)$ appear. Furthermore, the branching ratios of each decay channel are predicted. We expect more accurate measurements of these decays to better understand the nature of the states $f_{0}(500)$, $f_{0}(980)$ and $a_{0}(980)$.