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Localised Horizons and Holographic Thermodynamics: Supercooling in the 1/D Expansion

arXiv Eprint

Authors:

Prateek Agrawal, Gaurang Ramakant Kane, and Vazha Loladze

Abstract:

In holography, four-dimensional confining gauge theories are often modelled by five-dimensional Einstein--scalar gravity by choosing a specific form of the scalar potential. In a large class of non-conformal theories, we show that a predictive structure emerges for the thermal confinement transition by generalising the gravitational dual to $D+1$ dimensions and using a $1/D$ expansion. These results are independent of the details of the scalar potential, hinting towards universality. The black brane geometry dual to the deconfined phase can be analytically constructed due to its effects being localised near the horizon at leading order. The solution does not exist below a minimal temperature $T_{\rm min}$ and the maximum possible supercooling in the transition $\epsilon_{\rm sc} = 1-T_{\rm min}/T_{\rm c}$ is generically suppressed by a factor of $1/D^2$. Remarkably, the maximum supercooling at the leading order is set by the speed of sound in the deconfined phase of the gauge theory at the critical temperature, $\epsilon_{\rm sc}=c_s^2(T_{\rm c})/2$. These predictions agree with explicit calculations in an exponential superpotential, improved holography, and the thermal transition in $\mathcal{N}=4$ super Yang--Mills on a sphere.
Details from ArXiV

Evolution of Generic Varying-Tension Cosmic Strings in Expanding Spacetimes

International Journal of Modern Physics A World Scientific Pub Co Pte Ltd (2026) S0217751X26501587

Authors:

Hubert LAU Sze Chun, Joseph P Conlon

Abstract:

It has recently been realised that strings with time-dependent tensions exhibit interesting dynamics; in particular, when the tension decreases loops of string can grow and possibly percolate. We extend previous analytic studies of strings with time-dependent tensions to numerical studies of non-circular loops. We use numerical solvers and machine learning techniques to explore the dynamics of non-circular string loops with radii close to the Hubble scale.
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Abundant production of scalars and axions from phase transition bubble expansion

arXiv Eprint

Authors:

Isabel Garcia Garcia, Gaurang Ramakant Kane, John March-Russell, and Andrea Paolini

Abstract:

We revisit aspects of particle production during cosmological first-order phase transitions, and show that the expansion of true-vacuum bubbles can be a copious source of particle production. Specifically, for a massive spin-0 field linearly coupled to the bubble profile, spherical bubbles expanding even at \emph{constant} radial velocity efficiently produce particles until the local-rest-frame radius of curvature of the bubble wall exceeds the particle Compton wavelength -- contrary to the expectation that walls moving at constant speed cannot radiate. We compute the momentum spectrum of the produced particles for both accelerated and constant-velocity expansion histories, identify the regimes of coherent and incoherent production, quantify the validity of the perturbative treatment, and show that this mechanism can parametrically dominate other production processes of feebly coupled particles, including freeze-in. Our results apply to many models of light, feebly coupled particles studied in the literature, providing new sources of dark radiation and dark matter. In particular, a first-order deconfinement-confinement transition in a hidden Yang-Mills sector can abundantly produce axion-like particles, leading to dark radiation and/or dark matter signatures over large regions of parameter space.
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Metastable cosmic strings are broken at the start

Journal of High Energy Physics Springer 2026:7 (2026) 214

Authors:

Lorenzo Tranchedone, Ethan Carragher, Edward Hardy, Natálie van IJcken Koscelanská

Abstract:

We show that metastable cosmic strings break at early times, either via finite-temperature effects or by attaching to pre-existing monopoles during network percolation. The resulting segments can be initially super-horizon in size and thus persist for a significant amount of time. If the strings do not re-percolate, the network’s eventual destruction is typically due to this early-time breaking rather than late-time quantum tunnelling. Survival of strings to epochs probed by NANOGrav requires m2 M/µ ≳ 103 , where mM and µ are the monopole mass and the string tension respectively, over an order of magnitude larger than previous estimates. We also revisit quantum-tunnelling induced breaking. Results from numerical simulations suggest that this occurs mainly at rare high-tension points on the strings, yielding a rate much larger than is usually assumed. We briefly discuss the related scenario of flux tubes in a dark QCD-like hidden sector with dark-quark masses above the confinement scale.
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Constraining the Prompt Atmospheric Neutrino Flux combining IceCube’s Cascade and Track samples

European Physical Journal C 86:7 (2026) 814

Authors:

R Abbasi, M Ackermann, J Adams, SK Agarwalla, JA Aguilar, M Ahlers, JM Alameddine, S Ali, NM Amin, K Andeen, C Argüelles, Y Ashida, S Athanasiadou, SN Axani, R Babu, X Bai, J Baines-Holmes, A Balagopal V., SW Barwick, S Bash, V Basu, R Bay, JJ Beatty, J Becker Tjus, P Behrens, J Beise, C Bellenghi, S Benkel, S BenZvi, D Berley, E Bernardini, DZ Besson, E Blaufuss, L Bloom, S Blot, I Bodo, F Bontempo, JY Book Motzkin, C Boscolo Meneguolo, S Böser, O Botner, J Böttcher, J Braun, B Brinson, Z Brisson-Tsavoussis, RT Burley, D Butterfield, MA Campana, K Carloni, J Carpio, S Chattopadhyay, N Chau, Z Chen, D Chirkin, S Choi, BA Clark, P Coleman, GH Collin, DA Coloma Borja, A Connolly, JM Conrad, DF Cowen, C De Clercq, JJ DeLaunay, D Delgado, T Delmeulle, S Deng, P Desiati, KD de Vries, G de Wasseige, T DeYoung, JC Díaz-Vélez, S DiKerby, T Ding, M Dittmer, A Domi, L Draper, L Dueser, D Durnford, K Dutta, MA DuVernois, T Ehrhardt, L Eidenschink, A Eimer, C Eldridge, P Eller, E Ellinger, D Elsässer, R Engel, H Erpenbeck, W Esmail, S Eulig, J Evans, PA Evenson, KL Fan, K Fang, K Farrag, AR Fazely, A Fedynitch, N Feigl, C Finley, L Fischer, D Fox, A Franckowiak, S Fukami, P Fürst, J Gallagher, E Ganster, A Garcia, M Garcia, G Garg, E Genton, L Gerhardt, A Ghadimi, C Glaser, T Glüsenkamp, JG Gonzalez, S Goswami, A Granados, D Grant, SJ Gray, S Griffin, S Griswold, KM Groth, D Guevel, C Günther, P Gutjahr, C Ha, C Haack, A Hallgren, L Halve, F Halzen, L Hamacher, M Ha Minh, M Handt, K Hanson, J Hardin, AA Harnisch, P Hatch, A Haungs, J Häußler, K Helbing, J Hellrung, B Henke, L Hennig, F Henningsen, L Heuermann, R Hewett, N Heyer, S Hickford, A Hidvegi, C Hill, GC Hill, R Hmaid, KD Hoffman, D Hooper, S Hori, K Hoshina, M Hostert, W Hou, M Hrywniak, T Huber, K Hultqvist, K Hymon, A Ishihara, W Iwakiri, M Jacquart, S Jain, O Janik, M Jansson, M Jeong, M Jin, N Kamp, D Kang, W Kang, A Kappes, L Kardum, T Karg, M Karl, A Karle, A Katil, M Kauer, JL Kelley, M Khanal, A Khatee Zathul, A Kheirandish, H Kimku, J Kiryluk, C Klein, SR Klein, Y Kobayashi, A Kochocki, R Koirala, H Kolanoski, T Kontrimas, L Köpke, C Kopper, DJ Koskinen, P Koundal, M Kowalski, T Kozynets, A Kravka, N Krieger, J Krishnamoorthi, T Krishnan, K Kruiswijk, E Krupczak, A Kumar, E Kun, N Kurahashi, N Lad, C Lagunas Gualda, L Lallement Arnaud, MJ Larson, F Lauber, JP Lazar, K Leonard DeHolton, A Leszczyńska, C Li, J Liao, C Lin, QR Liu, YT Liu, M Liubarska, C Love, L Lu, F Lucarelli, W Luszczak, Y Lyu, M Macdonald, J Madsen, E Magnus, Y Makino, E Manao, S Mancina, A Mand, IC Mariş, S Marka, Z Marka, L Marten, I Martinez-Soler, R Maruyama, J Mauro, F Mayhew, F McNally, K Meagher, S Mechbal, A Medina, M Meier, Y Merckx, L Merten, J Mitchell, L Molchany, S Mondal, T Montaruli, RW Moore, Y Morii, A Mosbrugger, M Moulai, D Mousadi, E Moyaux, T Mukherjee, R Naab, M Nakos, U Naumann, J Necker, L Neste, M Neumann, H Niederhausen, MU Nisa, K Noda, A Noell, A Novikov, A Obertacke, V O’Dell, A Olivas, R Orsoe, J Osborn, E O’Sullivan, V Palusova, H Pandya, A Parenti, N Park, V Parrish, EN Paudel, L Paul, C Pérez de los Heros, T Pernice, TC Petersen, J Peterson, M Plum, A Pontén, V Poojyam, Y Popovych, M Prado Rodriguez, B Pries, R Procter-Murphy, GT Przybylski, L Pyras, C Raab, J Rack-Helleis, N Rad, M Ravn, K Rawlins, Z Rechav, A Rehman, I Reistroffer, E Resconi, S Reusch, CD Rho, W Rhode, L Ricca, B Riedel, A Rifaie, EJ Roberts, M Rongen, A Rosted, C Rott, T Ruhe, L Ruohan, D Ryckbosch, J Saffer, D Salazar-Gallegos, P Sampathkumar, A Sandrock, G Sanger-Johnson, M Santander, S Sarkar, M Scarnera, P Schaile, M Schaufel, H Schieler, S Schindler, L Schlickmann, B Schlüter, F Schlüter, N Schmeisser, T Schmidt, FG Schröder, L Schumacher, S Schwirn, S Sclafani, D Seckel, L Seen, M Seikh, S Seunarine, PA Sevle Myhr, R Shah, S Shah, S Shefali, N Shimizu, B Skrzypek, R Snihur, J Soedingrekso, D Soldin, P Soldin, G Sommani, C Spannfellner, GM Spiczak, C Spiering, J Stachurska, M Stamatikos, T Stanev, T Stezelberger, T Stürwald, T Stuttard, GW Sullivan, I Taboada, S Ter-Antonyan, A Terliuk, A Thakuri, M Thiesmeyer, WG Thompson, J Thwaites, S Tilav, K Tollefson, S Toscano, D Tosi, A Trettin, AK Upadhyay, K Upshaw, A Vaidyanathan, N Valtonen-Mattila, J Valverde, J Vandenbroucke, T Van Eeden, N van Eijndhoven, L Van Rootselaar, J van Santen, J Vara, F Varsi, M Venugopal, M Vereecken, S Vergara Carrasco, S Verpoest, D Veske, A Vijai, J Villarreal, C Walck, A Wang, EHS Warrick, C Weaver, P Weigel, A Weindl, J Weldert, AY Wen, C Wendt, J Werthebach, M Weyrauch, N Whitehorn, CH Wiebusch, DR Williams, L Witthaus, M Wolf, G Wrede, XW Xu, JP Yanez, Y Yao, E Yildizci, S Yoshida, R Young, F Yu, S Yu, T Yuan, S Yun-Cárcamo, A Zander Jurowitzki, A Zegarelli, S Zhang, Z Zhang, P Zhelnin, P Zilberman

Abstract:

The IceCube Neutrino Observatory has observed a diffuse flux of high-energy astrophysical neutrinos for more than a decade. A relevant background to the astrophysical flux is prompt atmospheric neutrinos, originating from the decay of charmed mesons produced in cosmic-ray-induced air showers. The production rate of charmed mesons in the very forward phase space of hadronic interactions, and consequently, the prompt neutrino flux, remains uncertain and has not yet been observed by neutrino detectors. An accurate measurement of this flux would enhance our understanding of fundamental particle physics such as hadronic interactions in high-energy cosmic-ray-induced air showers and the nucleon structure. Furthermore, an experimental characterization of this background flux will improve the precision of astrophysical neutrino flux spectral measurements. In this work, we perform a combined fit of cascade-like and track-like neutrino events in IceCube to constrain the prompt atmospheric neutrino flux. Given that the prompt flux is a sub-dominant contribution, treating systematic uncertainties arising from the potential mis-modeling of the conventional and astrophysical neutrino fluxes is critical for its measurement. Our analysis yields a non-zero best-fit result, which is, however, consistent with the null hypothesis of no prompt flux within one standard deviation. Consequently, we establish an upper bound on the flux at 4×10-16$$4\times 10^{-16}$$ (GeV m2$$^2$$ s sr)-1$$^{-1}$$ at 10TeV.
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