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1. Theoretical and experimental constraints for the equation of state of dense and hot matter

   https://doi.org/10.1007/s41114-024-00049-6  

   Kumar, Rajesh; Dexheimer, Veronica; Jahan, Johannes; Noronha, Jorge; Noronha-Hostler, Jacquelyn; Ratti, Claudia; Yunes, Nico; Nava_Acuna, Angel_Rodrigo; Alford, Mark; Anik, Mahmudul_Hasan; et al (June 2024, Living Reviews in Relativity)

   Abstract This review aims at providing an extensive discussion of modern constraints relevant for dense and hot strongly interacting matter. It includes theoretical first-principle results from lattice and perturbative QCD, as well as chiral effective field theory results. From the experimental side, it includes heavy-ion collision and low-energy nuclear physics results, as well as observations from neutron stars and their mergers. The validity of different constraints, concerning specific conditions and ranges of applicability, is also provided. 

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2. The explanatory nature of constraints: Law-based, mathematical, and causal

   https://doi.org/10.1007/s11229-023-04281-5  

   Ross, Lauren N. (August 2023, Synthese)

   This paper provides an analysis of explanatory constraints and their role in scientific explanation. This analysis clarifies main characteristics of explanatory constraints, ways in which they differ from “standard” explanatory factors, and the unique roles they play in scientific explanation. While current philosophical work appreciates two main types of explanatory constraints, this paper suggests a new taxonomy: law-based constraints, mathematical constraints, and causal constraints. This classification helps capture unique features of constraint types, the different roles they play in explanation, and it includes causal constraints, which are often overlooked in this literature. 

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3. A Formal Model for Resiliency-Aware Deployment of SDN: A SCADA-Based Case Study

   https://doi.org/10.23919/CNSM46954.2019.9012715  

   Jakaria, A H; Rahman, Mohammad Ashiqur; Gokhale, Aniruddha (October 2019, 15th International Conference on Network and Service Management (CNSM))

   The supervisory control and data acquisition (SCADA) network in a smart grid requires to be reliable and efficient to transmit real-time data to the controller. Introducing SDN into a SCADA network helps in deploying novel grid control operations, as well as, their management. As the overall network cannot be transformed to have only SDN-enabled devices overnight because of budget constraints, a systematic deployment methodology is needed. In this work, we present a framework, named SDNSynth, that can design a hybrid network consisting of both legacy forwarding devices and programmable SDN-enabled switches. The design satisfies the resiliency requirements of the SCADA network, which are specified with respect to a set of identified threat vectors. The deployment plan primarily includes the best placements of the SDN-enabled switches. The plan may include one or more links to be installed newly. We model and implement the SDNSynth framework that includes the satisfaction of several requirements and constraints involved in the resilient operation of the SCADA. It uses satisfiability modulo theories (SMT) for encoding the synthesis model and solving it. We demonstrate SDNSynth on a case study and evaluate its performance on different synthetic SCADA systems. 

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4. Cosmology of single species hidden dark matter

   https://doi.org/10.1088/1475-7516/2025/05/077  

   Lin, Weikang; Chen, Xingang; Ganjoo, Himanish; Hou, Liqiang; Mack, Katherine J (May 2025, Journal of Cosmology and Astroparticle Physics)

   Abstract Cosmology and astrophysics provide various ways to study the properties of dark matter even if they have negligible non-gravitational interactions with the Standard Model particles and remain hidden. We study a type of hidden dark matter model in which the dark matter is completely decoupled from the Standard Model sector except gravitationally, and consists of a single species with conserved comoving particle number and conserved comoving entropy. This category of hidden dark matter includes models that act as warm dark matter but is more general. In particular, in addition to having an independent temperature from the Standard Model sector, it includes cases in which dark matter is in its own kinetic equilibrium or is free-streaming, obeys fermionic or bosonic statistics, and processes a chemical potential that controls the particle occupation number. While the usual parameterization using the free-streaming scale or the particle mass no longer applies, we show that all cases can be well approximated by a set of functions parameterized by only one parameter as long as the chemical potential is nonpositive: the characteristic scale factor at the time of the relativistic-to-nonrelativistic transition. We study the constraints from Big Bang Nucleosynthesis, the cosmic microwave background, the Lyman-α forest, and the smallest halo mass. We show that the most significant phenomenological impact is the suppression of the small-scale matter power spectrum — a typical feature when the dark matter has a velocity dispersion or pressure at early times. So far, the Lyman-α forest and the small dark matter halo population provide the strongest constraints, limiting the transition redshift to be larger than ∼6.2×10⁷. 

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5. Universal deformations and inhomogeneities in isotropic Cauchy elasticity

   https://doi.org/10.1098/rspa.2024.0229  

   Yavari, Arash (July 2024, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences)

   For a given class of materials, universal deformations are those deformations that can be maintained in the absence of body forces and by applying solely boundary tractions. For inhomogeneous bodies, in addition to the universality constraints that determine the universal deformations, there are extra constraints on the form of the material inhomogeneities—universal inhomogeneity constraints. Those inhomogeneities compatible with the universal inhomogeneity constraints are called universal inhomogeneities. In a Cauchy elastic solid, stress at a given point and at an instance of time is a function of strain at that point and that exact moment in time, without any dependence on prior history. A Cauchy elastic solid does not necessarily have an energy function, i.e. Cauchy elastic solids are, in general, non-hyperelastic (or non-Green elastic). In this paper, we characterize universal deformations in both compressible and incompressible inhomogeneous isotropic Cauchy elasticity. As Cauchy elasticity includes hyperelasticity, one expects the universal deformations of Cauchy elasticity to be a subset of those of hyperelasticity both in compressible and incompressible cases. It is also expected that the universal inhomogeneity constraints to be more stringent than those of hyperelasticity, and hence, the set of universal inhomogeneities to be smaller than that of hyperelasticity. We prove the somewhat unexpected result that the sets of universal deformations of isotropic Cauchy elasticity and isotropic hyperelasticity are identical, in both the compressible and incompressible cases. We also prove that their corresponding universal inhomogeneities are identical as well. 

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