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1. Generalized Einstein relations between absorption and emission spectra at thermodynamic equilibrium

   https://doi.org/10.1073/pnas.2410280121  

   Ryu, Jisu; Yeola, Sarang; Jonas, David M (September 2024, Proceedings of the National Academy of Sciences)

   We present Einstein coefficient spectra and a detailed-balance derivation of generalized Einstein relations between them that is based on the connection between spontaneous and stimulated emission. If two broadened levels or bands overlap in energy, transitions between them need not be purely absorptive or emissive. Consequently, spontaneous emission can occur in both transition directions, and four Einstein coefficient spectra replace the three Einstein coefficients for a line. At equilibrium, the four different spectra obey five pairwise relationships and one lineshape generates all four. These relationships are independent of molecular quantum statistics and predict the Stokes’ shift between forward and reverse transitions required by equilibrium with blackbody radiation. For Boltzmann statistics, the relative strengths of forward and reverse transitions depend on the formal chemical potential difference between the initial and final bands, which becomes the standard chemical potential difference for ideal solutes. The formal chemical potential of a band replaces both the energy and degeneracy of a quantum level. Like the energies of quantum levels, the formal chemical potentials of bands obey the Rydberg-Ritz combination principle. Each stimulated Einstein coefficient spectrum gives a frequency-dependent transition cross-section. Transition cross-sections obey causality and a detailed-balance condition with spontaneous emission, but do not directly obey generalized Einstein relations. Even with an energetic width much less than the photon energy, a predominantly absorptive forward transition with an energetic width much greater than the thermal energy can have such an extreme Stokes’ shift that its reverse transition cross-section becomes predominantly absorptive rather than emissive. 

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2. Matching relations for decoupling in the standard model at two loops and beyond

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   Martin, Stephen P. (February 2019, Physical Review D)
3. Broadening of universal relations at the birth and death of a neutron star

   https://doi.org/10.1103/PhysRevD.109.083040  

   Guedes, Victor; Lau, Shu_Yan; Chirenti, Cecilia; Yagi, Kent (April 2024, Physical Review D)
4. Equivalence relations and determinacy

   https://doi.org/10.1142/S0219061322500039  

   Crone, Logan; Fishman, Lior; Jackson, Stephen (April 2022, Journal of Mathematical Logic)

   We introduce the notion of [Formula: see text]-determinacy for [Formula: see text] a pointclass and [Formula: see text] an equivalence relation on a Polish space [Formula: see text]. A case of particular interest is the case when [Formula: see text] is the (left) shift-action of [Formula: see text] on [Formula: see text] where [Formula: see text] or [Formula: see text]. We show that for all shift actions by countable groups [Formula: see text], and any “reasonable” pointclass [Formula: see text], that [Formula: see text]-determinacy implies [Formula: see text]-determinacy. We also prove a corresponding result when [Formula: see text] is a subshift of finite type of the shift map on [Formula: see text]. 

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5. Circular economy disclaimers: Rethinking property relations at the end of cheap nature

   https://doi.org/10.3389/frsus.2022.1007802  

   Isenhour, Cindy; Berry, Brieanne; Victor, Erin (January 2023, Frontiers in Sustainability)

   Converging environmental crises have inspired a movement to shift dominant economic forms away from linear “take-make-waste” models and toward more circular forms that reimagine discarded materials as valuable resources. With the coming “end of cheap nature”, this invitation to reimagine waste as something more than “the political other of capitalist value” is seen as both an environmental necessity and an opportunity for green growth. Less often discussed is that the circular economy, in its reconfiguration of value, also has the potential to reshape contemporary property relations and dismantle existing forms of circularity. In this paper, we explore potential shifts in property relations through an analysis of three strategies often imagined as key to facilitating the transition to circularity—extended producer responsibility, repair, and online resale. Each case synthesizes existing research, public discourse, and findings from a series of focus groups and interviews with circular economy professionals. While this research is preliminary and demands additional research, all three cases suggest caution given the possibility that some circular economy strategies can concentrate value and control of existing materials stocks, dispossess those most vulnerable, and alienate participants in existing reuse, recycling, and repair markets. Drawing on and adapting Luxemburg's concept of primitive accumulation, Tsing's ideas about salvage accumulation, Moore's work on commodity frontiers and recent research which encourages more attention to processes of commoning—we argue that without careful attention to relations of power and justice in conceptualizations of ownership and the collective actions necessary to transform our economic formsin common, transitions toward the circular economy have the potential to enclose the value of discards and exacerbate inequality. 

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