bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effective operator bases for beyond Standard Model scenarios: an EFT compendium for discoveries
Authors: Banerjee Upalaparna , Chakrabortty Joydeep , Prakash Suraj , Rahaman Shakeel Ur , Spannowsky Michael 
Published: January 2021

Abstract
It is not only conceivable but likely that the spectrum of physics beyond the Standard Model (SM) is non-degenerate. The lightest non-SM particle may reside close enough to the electroweak scale that it can be kinematically probed at high-energy experiments and on account of this, it must be included as an infrared (IR) degree of freedom (DOF) along with the SM ones. The rest of the non-SM particles are heavy enough to be directly experimentally inaccessible and can be integrated out. Now, to capture the effects of the complete theory, one must take into account the higher dimensional operators constituted of the SM DOFs and the minimal extension. This construction, BSMEFT, is in the same spirit as SMEFT but now with extra IR DOFs. Constructing a BSMEFT is in general the first step after establishing experimental evidence for a new particle. We have investigated three different scenarios where the SM is extended by additional (i) uncolored, (ii) colored particles, and (iii) abelian gauge symmetries. For each such scenario, we have included the most-anticipated and phenomenologically motivated models to demonstrate the concept of BSMEFT. In this paper, we have provided the full EFT Lagrangian for each such model up to mass dimension 6. We have also identified the CP, baryon (B), and lepton (L) number violating effective operators.
Quantum mechanical out-of-time-ordered-correlators for the anharmonic (quartic) oscillator
Authors: Romatschke Paul 
Published: January 2021

Abstract
Out-of-time-ordered correlators (OTOCs) have been suggested as a means to study quantum chaotic behavior in various systems. In this work, I calculate OTOCs for the quantum mechanical anharmonic oscillator with quartic potential, which is classically integrable and has a Poisson-like energy-level distribution. For low temperature, OTOCs are periodic in time, similar to results for the harmonic oscillator and the particle in a box. For high temperature, OTOCs exhibit a rapid (but power-like) rise at early times, followed by saturation consistent with 2〈x2〉T〈p2〉T at late times. At high temperature, the spectral form factor decreases at early times, bounces back and then reaches a plateau with strong fluctuations.
Search for like-sign dileptons plus two jets signal in the framework of the manifest left-right symmetric model
Authors: Roitgrund Aviad , Eilam Gad 
Published: January 2021

Abstract
The left-right symmetric model may present evidence of new physics at the era of the Large Hadron Collider (LHC). We use its framework to investigate the lepton number violating process pp → e±e±jj + X at the 14 TeV LHC. We show that for an integrated luminosity of 300 fb−1, the discovery contour of the right-handed boson WR and the right-handed electron neutrino Ne as a result of the pp → $$ {W}_R^{\pm } $$

W
R
±

→ e±N → e±e±jj process can be expanded upon considering an additional channel mediated by the right-handed doubly charged Higgs $$ {\delta}_R^{\pm \pm } $$

δ
R

±
±

, i.e. pp → $$ {W}_R^{\pm } $$

W
R
±

→ $$ {W}_R^{\mp \ast }{\delta}_R^{\pm \pm \ast } $$

W
R

∓
∗

δ
R

±
±
∗

→ e±e±jj.
The axion quality problem: global symmetry breaking and wormholes
Authors: Alvey James , Escudero Miguel 
Published: January 2021

Abstract
Continuous global symmetries are expected to be broken by gravity, which can lead to important phenomenological consequences. A prime example is the threat that this poses to the viability of the Peccei-Quinn solution to the strong CP problem. In this paper, we explore the impact of wormholes as a source of global symmetry breaking by gravity. We review the current status of wormholes and global symmetries and note that, surprisingly, the axion has a quality problem within non-perturbative Einstein gravity. Although these wormholes lead to a large breaking of global symmetries, we show that their effect is nonetheless relevant for the model building of gauge protected axions. We also find wormhole solutions within two scenarios: (i) an extended global symmetry group within Einstein gravity, and (ii) U(1) wormholes within the low-energy limit of an open String Theory. The former allows us to show that the concept of a global symmetry in General Relativity is somewhat ill-defined. The latter illustrates that for motivated values of the string coupling constant, axions appear to have a quality problem within the open String Theory we consider.
General solutions in Chern-Simons gravity and $$ T\overline{T} $$-deformations
Authors: Llabrés Eva 
Published: January 2021

Abstract
We find the most general solution to Chern-Simons AdS3 gravity in Fefferman-Graham gauge. The connections are equivalent to geometries that have a non-trivial curved boundary, characterized by a 2-dimensional vielbein and a spin connection. We define a variational principle for Dirichlet boundary conditions and find the boundary stress tensor in the Chern-Simons formalism. Using this variational principle as the departure point, we show how to treat other choices of boundary conditions in this formalism, such as, including the mixed boundary conditions corresponding to a $$ T\overline{T} $$
T

T
¯

-deformation.
Entrepreneurial lean thinking for sustainable business modeling: a workshop design for incumbent firms
Authors: Schwarz E. J. , Gregori P. , Krajger I. , Wdowiak M. A. 
Published: January 2021

AbstractIn times of increasing concerns and extensive political debates about social and environmental problems, incumbent firms are obliged to reduce their negative environmental impact by implementing sustainable business model innovation. Yet, realizing more sustainable business model variants entails several complexities and associated challenges that need to be overcome. To support this task, this article takes an entrepreneurship perspective on sustainable business model innovation and combines literature of business models and entrepreneurial lean thinking (ELT). In doing so, it derives a workshop design grounded in contemporary theory with state-of-the-art tools and methods. The workshop is framed as a stage-gate process facilitating the notions of ELT with iterative cycles of ‘create, test, and improve’ and spans the phases of opportunity identification, opportunity evaluation, opportunity development through sustainable business model design, and decision of opportunity exploitation. The article shows that ELT is an appropriate yet underutilized approach for sustainable business modeling. Further, it discusses how the workshop supports opportunities and mitigate pitfalls of ELT for sustainable business modeling. As such, the findings have theoretical implications for the intersection of sustainability and lean approaches in innovation research as well as implications for practitioners by providing a comprehensive framework to support sustainable business model innovation.
Modeling and “smart” prototyping human-in-the-loop interactions for AmI environments
Authors: Gil Miriam , Albert Manoli , Fons Joan , Pelechano Vicente 
Published: January 2021

AbstractAutonomous capabilities are required in AmI environments in order to adapt systems to new environmental conditions and situations. However, keeping the human in the loop and in control of such systems is still necessary because of the diversity of systems, domains, environments, context situations, and social and legal constraints, which makes full autonomy a utopia within the short or medium term. Human-system integration introduces an important number of challenges and problems that have to be solved. On the one hand, humans should interact with systems even in those situations where their attentional, cognitive, and physical resources are limited in order to perform the interaction. On the other hand, systems must avoid overwhelming the user with unnecessary actions. Therefore, appropriate user-centered methods for AmI development should be used to help designers analyze and design human-in-the-loop interactions in AmI environments. This paper presents a user-centered design method that defines a process with a set of tools and techniques that supports the process steps in order to systematically design, prototype, and validate human-in-the-loop (HiL) solutions. The process starts with the definition of the HiL design, which defines how the system cooperates with the human. This HiL design is built using a conceptual framework that focuses on achieving human-system interactions that get human attention and avoid obtrusiveness. Then, we provide a software infrastructure to generate a prototype based on the HiL design and validate it by having end-users use a web simulator. The feedback data generated during the prototype user validation is gathered and used by a machine learning tool that infers the user’s needs and preferences. Finally, these inferences are used to automatically enhance the human-in-the-loop designs and prototypes. We have validated the proposed method through a twofold perspective: an experiment to analyze the perception of interaction designers regarding their acceptance of the design method and another experiment to evaluate the usefulness of the “smart” prototyping technique. The results obtained point out the acceptability of the proposed method by designers and the useful adaptations provided by the “smart” prototyping technique to achieve a HiL design that adapts well to users’ preferences and needs.
Evolutionary histories and mycorrhizal associations of mycoheterotrophic plants dependent on saprotrophic fungi
Authors: Ogura-Tsujita Yuki , Yukawa Tomohisa , Kinoshita Akihiko 
Published: January 2021

AbstractMycoheterotrophic plants (MHPs) are leafless, achlorophyllous, and completely dependent on mycorrhizal fungi for their carbon supply. Mycorrhizal symbiosis is a mutualistic association with fungi that is undertaken by the majority of land plants, but mycoheterotrophy represents a breakdown of this mutualism in that plants parasitize fungi. Most MHPs are associated with fungi that are mycorrhizal with autotrophic plants, such as arbuscular mycorrhizal (AM) or ectomycorrhizal (ECM) fungi. Although these MHPs gain carbon via the common mycorrhizal network that links the surrounding autotrophic plants, some mycoheterotrophic lineages are associated with saprotrophic (SAP) fungi, which are free-living and decompose leaf litter and wood materials. Such MHPs are dependent on the forest carbon cycle, which involves the decomposition of wood debris and leaf litter, and have a unique biology and evolutionary history. MHPs associated with SAP fungi (SAP-MHPs) have to date been found only in the Orchidaceae and likely evolved independently at least nine times within that family. Phylogenetically divergent SAP Basidiomycota, mostly Agaricales but also Hymenochaetales, Polyporales, and others, are involved in mycoheterotrophy. The fungal specificity of SAP-MHPs varies from a highly specific association with a single fungal species to a broad range of interactions with multiple fungal orders. Establishment of symbiotic culture systems is indispensable for understanding the mechanisms underlying plant–fungus interactions and the conservation of MHPs. Symbiotic culture systems have been established for many SAP-MHP species as a pure culture of free-living SAP fungi is easier than that of biotrophic AM or ECM fungi. Culturable SAP-MHPs are useful research materials and will contribute to the advancement of plant science.
Hunting of mammals by central chimpanzees (Pan troglodytes troglodytes) in the Loango National Park, Gabon
Authors: Klein Harmonie , Bocksberger Gaëlle , Baas Pauline , Bunel Sarah , Théleste Erwan , Pika Simone , Deschner Tobias 
Published: January 2021

AbstractThe predation and consumption of animals are common behaviours in chimpanzees across tropical Africa. To date, however, relatively little is known concerning the hunting behaviour of central chimpanzees (Pan troglodytes troglodytes). Here, we provide the first direct observations of hunting behaviour by individuals of the newly habituated Rekambo community in the Loango National Park, Gabon. Over a period of 23 months (May 2017 to March 2019), we observed a total of 61 predation attempts on eight mammal species, including four monkey species. The two most frequently hunted species were two monkey species (Cercocebus torquatus,Cercopithecus nictitans), which are not hunted at other long-term field sites. The majority of predation events observed involved parties of an average of eight individuals, mainly adult males, with hunting success being higher with increasing numbers of participants. Hunting occurred all year round, but hunting rates increased in the dry season, the period of high fruit availability in the Loango National Park. These results are in line with the nutrient surplus hypothesis which explains seasonal variation in hunting behaviour in several populations of eastern chimpanzees (Pan troglodytes schweinfurthii: e.g., Mahale, Tanzania; Ngogo, Uganda). Finally, with a hunting frequency of 2.65 hunts per month, the Rekambo community had higher hunting rates than other sites (Bossou, Republic of Guinea; Kahuzi-Biega, Democratic Republic of Congo; Budongo, Uganda) where red colobus monkeys are also absent. We discuss these results and compare them to patterns at other long-term sites.
Machine learning models for the secondary Bjerknes force between two insonated bubbles
Authors: Chen Haiyan , Zeng Yue , Li Yi 
Published: January 2021

Abstract
The secondary Bjerknes force plays a significant role in the evolution of bubble clusters. However, due to the complex dependence of the force on multiple parameters, it is highly non-trivial to include its effects in the simulations of bubble clusters. In this paper, machine learning is used to develop a data-driven model for the secondary Bjerknes force between two insonated bubbles as a function of the equilibrium radii of the bubbles, the distance between the bubbles, the amplitude and the center frequency of the ultrasound wave. The sign of the force may change with the phase difference between the oscillating bubbles. Meanwhile, the magnitude of the force varies over several orders of magnitude, which poses a serious challenge for the usual machine learning models. To overcome this difficulty, the magnitudes and the signs of the force are separated and modelled separately. A nonlinear regression is obtained with a feed-forward network model for the logarithm of the magnitude, whereas the sign is modelled by a support-vector machine model. The principle, the practical aspects related to the training and validation of the machine models are introduced. The predictions from the models are checked against the values computed from the Keller–Miksis equations. The results show that the models are extremely efficient while providing accurate estimate of the force. The models make it computationally feasible for the future simulations of the bubble clusters to include the effects of the secondary Bjerknes force.

Graphic abstract
A “toy” model of biogeochemical dynamics on climate gradients
Authors: Vitousek Peter M. , Bateman Jesse Bloom , Chadwick Oliver A. 
Published: January 2021

AbstractWe used a simple “toy” model to aid in the evaluation of the controls of biogeochemical patterns along a climate gradient. The model includes simplified treatments of water balance (precipitation minus Potential Evapotranspiration), leaching, weathering of cation- and P-bearing minerals, N cycling and loss, biomass production, and biological N fixation. We use δ15N as a central integrator of biogeochemical processes, because δ15N integrates multiple pathways of N input, output, and transformation in ecosystems. The model simulated the location and magnitude of a peak in δ15N on a gradient on Kohala Volcano, Hawai‘i which peaked ~  + 14 ‰ in sites receiving ~ 3.5 cm/month average precipitation (− 1300 mm/year water balance); the model also captured a peak in total P in surface soil at intermediate levels of precipitation and water balance, and other biogeochemical features on the gradient. We then applied the model to understanding the patterns of and mechanisms underlying nutrient limitation to net primary production (NPP) and plant biomass on the gradient, testing for the existence and extent of N and P limitation by simulated additions of N and/or P in the model. Both a simulated symbiotic biological N fixer and a simulated non-fixer were limited by P supply across the gradient; the non-fixer was independently limited by N supply in wetter sites. By running the toy model with and without the influence of temperature, we demonstrated that water is the most important factor shaping biogeochemical patterns on this gradient.
A Retrospective on Teenage Pregnancy in Poland: Focussing on Empowerment and Support Variables to Challenge Stereotyping in the Context of Social Work
Authors: Odrowąż-Coates Anna , Kostrzewska Dagmara 
Published: January 2021

AbstractThe article focuses on selected predicators of successful and fulfilling teenage motherhood. It contains analysis of qualitative data, obtained through comprehensive interviews and field notes from social work practice, based on the personal experiences of teenage mothers and a court appointed family curator. Using herstory perspective, it aims to present positive examples of teenage motherhood as a source of empowerment and independence, to unveil and combat stereotypical views on adolescent mothers in Poland. Moreover, the authors discuss systemic issues and challenges as well as a social stigma created by public opinion and aim to challenge harmful stereotyping. The article contributes to social work practice for the purpose of enhancement of the international comparative studies in this field.
Semiparametric regression based on quadratic inference function for multivariate failure time data with auxiliary information
Authors: Yan Feifei , Zhu Lin , Liu Yanyan , Cai Jianwen , Zhou Haibo 
Published: January 2021

AbstractThis paper deals with statistical inference procedure of multivariate failure time data when the primary covariate can be measured only on a subset of the full cohort but the auxiliary information is available. To improve efficiency of statistical inference, we use quadratic inference function approach to incorporate the intra-cluster correlation and use kernel smoothing technique to further utilize the auxiliary information. The proposed method is shown to be more efficient than those ignoring the intra-cluster correlation and auxiliary information and is easy to implement. In addition, we develop a chi-squared test for hypothesis testing of hazard ratio parameters. We evaluate the finite-sample performance of the proposed procedure via extensive simulation studies. The proposed approach is illustrated by analysis of a real data set from the study of left ventricular dysfunction.
Discount, transparency and announcements effects of equity rights offerings: international evidence
Authors: Bobenhausen Nils-Christian , Salzmann Astrid Juliane 
Published: January 2021

AbstractEquity rights offerings and their respective announcement effects have been studied extensively in the literature. Our study expands upon these studies and focuses on those announcement effects and the relation between the discount of an equity rights offering and the announcement effect. Previous theoretical and empirical analyses show that firms can signal their quality via the discount in an equity rights offering and demonstrate a negative relation between the discount and the announcement effect. We argue that this link is only relevant in environments where signalling is possible and necessary. These are financial markets with a particularly low level of capital market transparency, i.e. high information asymmetry. We calculate announcement effects for an international sample of equity rights offerings and show that the negative effect of the discount on announcement effects can only be observed in environments with a low capital market transparency. Hence, our study estimates announcement effects across several different countries and is thus among the first to analyse signalling considerations for equity rights offerings in different transparency environments.
Decision-making for nature’s contributions to people in the Cape Floristic Region: the role of values, rules and knowledge
Authors: Topp Emmeline N. , Loos Jacqueline , Martín-López Berta 
Published: January 2021

AbstractNature conservation on privately owned land depends on land managers’ decision-making. Interactions between values, rules and knowledge (vrk) underpin decision-making, thus, it is important to understand these interactions to support conservation intentions. We investigated how different sets of vrk determine the decision-making context regarding the management and conservation of renosterveld, a critically endangered ecosystem in the Cape Floristic Region, and how this relates to land managers’ perceptions of nature’s contributions to people (NCP). From interviews with thirty land managers, we identified nine value types, four rule types, three knowledge types and 13 different NCP. We found that different vrk combinations can be grouped into three decision-making contexts: Bottom-up conservation, Top-down conservation and Utility. Each context is associated with the perception of different beneficial and detrimental NCP. Regulating NCP are perceived across all contexts, whereas more non-material NCP are associated with a Bottom-up conservation context and relational values, such as family ties. The prevalence of relational values in Bottom-up and Top-down conservation contexts illustrates the complexity and non-substitutability of the dynamic relationships between renosterveld and people. This indicates the importance of plural valuation in nature conservation to foster diverse NCP provided by renosterveld.
Nanomechanical Response of Pulsed Tungsten Inert Gas Welded Titanium Alloy by Nanoindentation and Atomic Force Microscopy
Authors: Hassaan Muhammad , Junaid Massab , Shahbaz Tauheed , Ilyas Muhammad , Khan Fahd Nawaz , Haider Julfikar 
Published: January 2021

AbstractNanohardness and Effective Elastic Moduli were measured for pulsed-Gas Tungsten Arc Welded Ti-5Al-2.5Sn alloy using autogenous mode through nanoindentation and atomic force microscopy. Experiments were conducted using a Berkovich tip on nanoindentor with Berkovich tip and elliptical pile ups were measured using an Atomic Force Microscope. Nanohardness and effective elastic moduli were calculated in the base metal, heat affected zone and fusion zone of the weldments using different approaches namely Oliver–Pharr method, AFM analysis and work of indentation. A significant difference was observed in the nanomechanical response using these approaches which was attributed to the pile up morphology of the nano indents. The presence of residual stress in the weldments also significantly influenced the nanohardness profile across the weld joint. The present research suggested that the work of indentation is most suitable for assessment of nanomechanical properties of Ti-5Al-2.5Sn alloy weldments among the three techniques studied in this investigation.