This article examines how compact astronomical objects behave under the theoretical framework of $$f(R,L_m,T)$$ theory of gravity. We develop modified field equations by taking into consideration the static internal spacetime which is filled with the anisotropic fluid content. Applying two particular constraints related to the anisotropic pressure and radial metric function allows us to identify two new solutions to these gravitational equations. We obtain differential equations for both models, the integration of which yields constants that are established using matching criteria. The necessity for radial pressure to vanish at the hypersurface is also used to find these constants. Afterwards, for various values of the parameters involved in the considered modified model, we visually assess certain requirements whose fulfillment guarantees the viability of the model. For this purpose, we consider the observational data of a compact star 4U 1820-30. We deduce that both of our models meet the necessary stability and viability requirements. Notably, our study advances the understanding of compact stellar models by demonstrating how the considered theory of gravity modifies their evolutionary pattern compared to general relativity, and provides a robust framework for exploring matter-geometry coupling in future astrophysical research.

Pakistan

Azerbaijan

Tayyab Naseer

M. Sharif

M. Waqas

Saudi Arabia

Nazek Alessa

Mohamed Eid

Stable anisotropic solutions for compact stars in matter-geometry coupled theory under some specific spacetimes

<p><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mtext>DMRadio-</mtext><msup><mrow><mi mathvariant="normal">m</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math> is an experimental search for dark matter axions. It uses a solenoidal dc magnetic field to convert an axion dark-matter signal to an ac electromagnetic response in a coaxial copper pickup. The current induced by this axion signal is measured by dc SQUIDs. <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mtext>DMRadio-</mtext><msup><mrow><mi mathvariant="normal">m</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math> is designed to be sensitive to Kim-Shifman-Vainshtein-Zakharov (KSVZ) and Dine-Fischler-Srednicki-Zhitnisky (DFSZ) QCD axion models in the 10–200 MHz (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>41</mn><mtext> </mtext><mtext> </mtext><mi>neV</mi><mo>/</mo><msup><mi>c</mi><mn>2</mn></msup><mi>–</mi><mrow><mn>0.83</mn><mtext> </mtext><mtext> </mtext><mi mathvariant="normal">μ</mi><mi>eV</mi><mo>/</mo><msup><mi>c</mi><mn>2</mn></msup></mrow></mrow></math>) range, and to axions with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>g</mi><mrow><mi>a</mi><mi>γ</mi><mi>γ</mi></mrow></msub><mo>=</mo><msub><mi>g</mi><mrow><mi>a</mi><mi>γ</mi><mi>γ</mi><mo>,</mo><mrow><mi>DFSZ</mi></mrow></mrow></msub><mo stretchy="false">(</mo><mn>30</mn><mtext> </mtext><mtext> </mtext><mi>MHz</mi><mo stretchy="false">)</mo><mo>=</mo><mn>1.87</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>17</mn></mrow></msup><mtext> </mtext><mtext> </mtext><msup><mrow><mi>GeV</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math> over 5–30 MHz as an extended goal. In this work, we present the electromagnetic modeling of the response of the experiment to an axion signal over the full frequency range of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mtext>DMRadio-</mtext><msup><mrow><mi mathvariant="normal">m</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math>, which extends from the low-frequency, lumped-element limit to a regime where the axion Compton wavelength is only a factor of 2 larger than the detector size. With these results, we determine the live time and sensitivity of the experiment. The primary science goal of sensitivity to DFSZ axions across 30–200 MHz can be achieved with a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mi>σ</mi></math> live scan time of 2.9 years.</p>

United States

A. AlShirawi

V. Ankel

C. Bartram

J. Begin

C. Bell

J.N. Benabou

L. Brouwer

S. Chaudhuri

H.M. Cho

J. Corbin

W. Craddock

S. Cuadra

A. Droster

J. Echevers

J.W. Foster

J.T. Fry

P.W. Graham

R. Henning

K.D. Irwin

F. Kadribasic

Y. Kahn

A. Keller

R. Kolevatov

S. Kuenstner

A. Kunder

N. Kurita

A.F. Leder

D. Li

N. Otto

J.L. Ouellet

K.M.W. Pappas

A. Phipps

N.M. Rapidis

B.R. Safdi

C.P. Salemi

M. Simanovskaia

J. Singh

P. Stark

E.C. van Assendelft

K. van Bibber

K. Wells

J. Wiedemann

L. Winslow

W.J. Wisniewski

D. Wright

A.K. Yi

B.A. Young

Electromagnetic modeling and science reach of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mtext>DMRadio-</mtext><msup><mrow><mi mathvariant="normal">m</mi></mrow><mrow><mn>3</mn></mrow></msup></mrow></math>

Combining toric geometry techniques and $$\mathcal {N}=2$$ supergravity formalisms, we study 5D black branes in the M-theory compactification on a four parameter Calabi–Yau threefold. First, we investigate 5D BPS and non-BPS black holes that are derived by wrapping M2-branes on non-holomorphic 2-cycles in such a toric Calabi–Yau manifold. Concretely, we provide the allowed electric charge regions of BPS and non-BPS black hole states that are obtained by surrounding M2-branes over appropriate 2-cycles. Then, we approach the black hole thermodynamic behavior by computing the entropy and the temperature. By evaluating the recombination factor, we examine the stability of such non-BPS black holes. Precisely, we find stable and unstable solutions depending on the allowed electric charge regions. After that, we study 5D black strings by wrapping M5-branes on non-holomorphic dual 4-cycles in the proposed toric Calabi–Yau manifold by focusing on the stability behaviors. In the allowed regions of the moduli space of the non-BPS stringy solutions, we find stable and unstable states depending on the magnetic charge values.

Morocco

A. Belhaj

H. Belmahi

A. Bouhouch

S. Ennadifi

M. Sedra

Black holes and black strings in M-theory on Calabi–Yau threefolds with four Kähler parameters

<p>We report on a search for sub-GeV dark matter (DM) particles interacting with electrons using the DAMIC-M prototype detector at the Modane Underground Laboratory. The data feature a significantly lower detector single <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> rate (factor 50) compared to our previous search, while also accumulating a 10 times larger exposure of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo>∼</mo><mn>1.3</mn><mtext> </mtext><mtext> </mtext><mi>kg</mi><mtext>−</mtext><mi>day</mi></mrow></math>. DM interactions in the skipper charge-coupled devices (CCDs) are searched for as groups of two or three adjacent pixels with a total charge between 2 and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>4</mn><mtext> </mtext><mtext> </mtext><msup><mi>e</mi><mo>−</mo></msup></math>. We find 144 candidates of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>2</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math> and 1 candidate of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>4</mn><mtext> </mtext><mtext> </mtext><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></mrow></math>, where 141.5 and 0.071, respectively, are expected from background. With no evidence of a DM signal, we place stringent constraints on DM particles with masses between 1 and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1000</mn><mtext> </mtext><mtext> </mtext><mi>MeV</mi><mo>/</mo><msup><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math> interacting with electrons through an ultralight or heavy mediator. For large ranges of DM masses below <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>1</mn><mtext> </mtext><mi>GeV</mi><mo>/</mo><msup><mrow><mi>c</mi></mrow><mrow><mn>2</mn></mrow></msup></mrow></math>, we exclude theoretically motivated benchmark scenarios where hidden-sector particles are produced as a major component of DM in the Universe through the freeze-in or freeze-out mechanisms.</p>

K. Aggarwal

I. Arnquist

Argentina

N. Avalos

France

X. Bertou

Spain

N. Castelló-Mor

A.E. Chavarria

J. Cuevas-Zepeda

A. Dastgheibi-Fard

C. De Dominicis

O. Deligny

J. Duarte-Campderros

E. Estrada

R. Gaïor

Switzerland

E.L. Gkougkousis

T. Hossbach

L. Iddir

B.J. Kavanagh

B. Kilminster

A. Lantero-Barreda

Canada

I. Lawson

A. Letessier-Selvon

H. Lin

P. Loaiza

A. Lopez-Virto

R. Lou

K.J. McGuire

S. Munagavalasa

J. Noonan

D. Norcini

S. Paul

P. Privitera

P. Robmann

B. Roach

M. Settimo

R. Smida

M. Traina

R. Vilar

R. Yajur

D. Venegas-Vargas

C. Zhu

Y. Zhu

Probing Benchmark Models of Hidden-Sector Dark Matter with DAMIC-M

In this article, the potential of water Cherenkov detectors equipped with multi-PMT modules for background-free upward-going neutrino detection and improved direction reconstruction is demonstrated. By analyzing signal time traces with transformer-based models, significant improvements in angular resolution are achieved compared to previous designs with larger PMTs. These detectors enable the reconstruction of neutrino directions with resolutions of approximately $$10^\circ $$ in azimuth and $$7^\circ $$ in zenith for high-signal events, corresponding to an overall opening angle of approximately $$10^\circ .$$ This design reduces saturation effects and enhances directional sensitivity, particularly for high-energy neutrinos. The results highlight the potential of WCD arrays as complementary tools for neutrino astronomy, particularly in the context of multimessenger observations of transient astrophysical sources. The nearly continuous operation and wide field of view of these detectors further enhance their suitability for real-time monitoring and alert generation.

J. Alvarez-Muñiz

Italy

R. Colalillo

Portugal

R. Conceição

B. González

V. Grieco

F. Guarino

M. Pimenta

B. Tomé

Enhancing neutrino reconstruction in water-Cherenkov air shower arrays using multi-photosensors

Non-geometric flux vacua have recently been revisited, leading to the remarkable discovery of isolated 4D $$ \mathcal{N} $$ = 1 supersymmetric Minkowski vacua. These constructions rely on the non-renormalization of the superpotential, which is supported by heuristic arguments. Given the significance of verifying the existence of these isolated M-theory-like vacua, we present alternative symmetry-based arguments that arrive at the same conclusion. Additionally, we leverage these symmetries to argue for the existence of unstable dS solutions as well as supersymmetric AdS solutions.

Shi Chen

Damian Heisteeg

Cumrun Vafa

Symmetries and M-theory-like vacua in four dimensions

We study higher-derivative corrections to the graviton scattering amplitude in M-theory, via the stress tensor correlator of 3d $$ \mathcal{N} $$ = 8 U($\textit{N}$) × U($\textit{N}$) ABJM theory (dual to graviton scattering in M-theory on AdS × $\textit{S}$ /$\textit{ℤ}$ ). We use the conformal bootstrap combined with an integral constraint derived from supersymmetric localization in order to constrain semishort OPE coefficients appearing in the stress tensor correlator. We obtain islands that are significantly more precise than those in previous studies that did not use the integral constraint. Using these islands, we can estimate the powers and coefficients in a large central charge expansion. This allows us to accurately read off the N LO contribution, from the protected $\textit{D}$ $\textit{R}$ correction, and also estimate the N LO contribution, from the unprotected $\textit{D}$ $\textit{R}$ correction.

United Kingdom

Shai Chester

Ross Dempsey

Silviu Pufu

Higher-derivative corrections in M-theory from precision numerical bootstrap

The chiral worldvolume theory of an M-theory boundary (the so-called M9 brane) is uniquely determined by supersymmetry and anomaly inflow. In this brief note we investigate whether alternative chiral boundary field contents may be allowed by anomaly cancellation once supersymmetry is dropped. Even then, anomaly inflow places stringent constraints on the gauge group $\textit{G}$ and matter content of the boundary worldvolume theory, which we determine explicitly. We find the most general solution to these constraints in the case where all matter fields are of the same chirality, for all simple Lie algebras except $$ {\mathfrak{sp}}_2 $$ , $$ {\mathfrak{su}}_{n\le 5} $$ , and $$ {\mathfrak{so}}_n $$ with 7 ≤ $\textit{n}$ ≤ 12, and find no solutions other than the supersymmetric $\textit{E}$ boundary of Hořava and Witten. However, when we extend our search to allow for any chirality in the matter fields, we find one minimal solution with gauge group $\textit{G}$ , charged matter in the 14, 27 and 77 representations, which satisfies all constraints in a non-trivial way. Therefore, it could in principle describe the low-energy theory of a novel nonsupersymmetric M-theory boundary condition, different from the Hořava-Witten proposal. We briefly discuss some consequences if this was indeed the case, such as the existence of a non-supersymmetric, exotic “$\textit{G}$ -string” CFT in 6d, and a novel, non-perturbative, heterotic-like 10d string with gauge group $\textit{G}$ × $\textit{G}$ .

Miguel Montero

not found

Mexico

Luis Zapata

M-theory boundaries beyond supersymmetry

We explore the impact of loop effects on positivity in effective field theories emerging in the infrared from unitary and causal microscopic dynamics. Focusing on massless particles coupled to gravity, we address the treatment of forward-limit divergences from loop discontinuities and establish necessary conditions for maintaining computational control in perturbation theory. While loop effects remain small, ensuring consistency in our approach leads to a significant impact on bounds, even at tree level.

Carl Beadle

Giulia Isabella

Davide Perrone

Sara Ricossa

Francesco Riva

Francesco Serra

The EFT bootstrap at finite $\textit{M}$

Germany

G. Buchalla

M. Capozi

A. Celis

G. Heinrich

Australia

L. Scyboz

Erratum: Higgs boson pair production in non-linear Effective Field Theory with full $\textit{m}$