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Self-Tracking Solutions for Asymptotic Scalar Fields

(2025)

Authors:

Martin Mosny, Joseph P Conlon, Edmund J Copeland
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A Prediction for Maximum Supercooling in SU(N) Confinement Transition

arXiv Preprint

Authors:

Prateek Agrawal, Gaurang Ramakant Kane, Vazha Loladze, and John March-Russell

Abstract:

The thermal confinement phase transition (PT) in SU(N) Yang-Mills theory is first-order for N\geq 3, with bounce action scaling as N^2. Remarkably, lattice data for the action include a small coefficient whose presence likely strongly alters the PT dynamics. We give evidence, utilizing insights from softly-broken SUSY YM models, that the small coefficient originates from a deconfined phase instability just below the critical temperature. We predict the maximum achievable supercooling in SU(N) theories to be a few percent, which can be tested on the lattice. We briefly discuss the potentially significant suppression of the associated cosmological gravitational wave signals.
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Spin-dependent dark matter scattering in quasi-two-dimensional magnets

Physical Review D American Physical Society (APS) 112:3 (2025) 035030

Authors:

Giacomo Marocco, John Wheater

Abstract:

We study the prospects of detecting dark matter coupled to the spin of the electron, such that it may scatter and excite magnons—collective excitations of electronic spins. We show that materials exhibiting long-range magnetic order where the spins are coupled only along a plane may act as directional dark matter detectors. These quasi-two-dimensional materials possess anisotropic dispersion relations and structure functions which induce a sidereal modulation in the excitation rate. We calculate the expected signal rate for some candidate (anti)ferromagnets, demonstrating a possible route to the direct detection of spin-dependent dark matter in the keV to MeV mass range.
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Anomalous scaling of linear power corrections

(2025)

Authors:

Casey Farren-Colloty, Jack Helliwell, Rtvik Patel, Gavin P Salam, Silvia Zanoli
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De Sitter space constraints on brane tensions and couplings

Journal of High Energy Physics Springer 2025:7 (2025) 221

Authors:

Saquib Hassan, Georges Obied, John March-Russell

Abstract:

We argue for the existence of bounds on the tensions of p-branes in de Sitter space in terms of the Hubble rate and the strength of a class of Chern-Simons-like couplings. The world-volume couplings involve Abelian 1-form gauge fields in the bulk and possibly field strengths intrinsic to the brane. In many cases these couplings are the D-brane Chern-Simons terms present in string theory, while in other cases they are the interactions of axion domain walls with U(1) fields. Our arguments use the same logic and assumptions as the recent Festina Lente proposal (thus utilizing the properties of Nariai de Sitter black holes) and generalize it to extended objects, thereby providing a bottom-up set of constraints independent of any particular UV completion. We compare these bounds to the properties of (wrapped) D-branes in Type II string theory in the weak coupling limit, under the assumption that these properties are not modified significantly in de Sitter constructions. We find that all constraints are satisfied by D-branes, providing further evidence for the Festina Lente conjecture. For the particular case of 2-branes with Chern-Simons interactions we obtain a bound, which however can be evaded if the theory contains a light axion. Similarly, we find the bounds do not apply to axion domain walls due to the presence of the axion.
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