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

   Kumar, Rajesh; Dexheimer; Veronica; Jahan, Johannes; Noronha, Jorge; Noronha_Hostler, Jacquelyn; Ratti, Claudia (June 2024, Living Reviews in Relativity)

   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. 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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3. 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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4. Integrated column generation for volunteer‐based delivery assignment and route optimization

   https://doi.org/10.1111/mice.13439  

   Atik, Asya; Li, Kuangying; Hajibabai, Leila; Hajbabaie, Ali (June 2025, Computer-Aided Civil and Infrastructure Engineering)

   Abstract This study develops an integrated delivery assignment and route planning strategy for food banking operations, considering food supply and demand constraints, food item restrictions, and vehicle capacity constraints. A mixed‐integer linear model is formulated to maximize the total demand served and minimize the total travel cost imposed on delivery volunteers. An integrated solution algorithm is developed that includes Lagrangian relaxation and column generation. The algorithm decomposes the problem into assignment and routing components and solves each iteratively. The proposed methodology is applied to a case study in Wake County, NC. A series of sensitivity analyses are conducted to draw insights. The numerical results demonstrate the proposed methodology's capacity to solve complex problems in food delivery operations efficiently. 

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5. (Mis)align: a simple dynamic framework for modeling interpersonal coordination

   https://doi.org/10.1038/s41598-023-41516-4  

   Miao, Grace Qiyuan; Dale, Rick; Galati, Alexia (December 2023, Scientific Reports)

   Abstract As people coordinate in daily interactions, they engage in different patterns of behavior to achieve successful outcomes. This includes both synchrony—the temporal coordination of the same behaviors at the same time—and complementarity—the coordination of the same or different behaviors that may occur at different relative times. Using computational methods, we develop a simple framework to describe the interpersonal dynamics of behavioral synchrony and complementarity over time, and explore their task-dependence. A key feature of this framework is the inclusion of a task context that mediates interactions, and consists of active, inactive, and inhibitory constraints on communication. Initial simulation results show that these task constraints can be a robust predictor of simulated agents’ behaviors over time. We also show that the framework can reproduce some general patterns observed in human interaction data. We describe preliminary theoretical implications from these results, and relate them to broader proposals of synergistic self-organization in communication. 

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