We use the spectral lag catalog of 46 short GRBs aggregated by Xiao et al. (Astrophys J Lett 924:L29, 2022), to carry out an independent search for Lorentz invariance violation (LIV). For this purpose, we use a power-law model as a function of energy for the intrinsic astrophysical induced spectral lags. The expansion history of the universe needed for constraining LIV was obtained in a non-parametric method using cosmic chronometers. We use Bayesian model comparison to determine if the aforementioned spectral lags show evidence for LIV as compared to only astrophysically induced lags. We do not find any evidence for LIV, and obtain 95% CL lower limits on the corresponding energy scale to be  $$4 \times 10^{15}$$  <math> <mrow> <mn>4</mn> <mo>×</mo> <msup> <mn>10</mn> <mn>15</mn> </msup> </mrow> </math>   GeV and  $$6.8 \times 10^{9}$$  <math> <mrow> <mn>6.8</mn> <mo>×</mo> <msup> <mn>10</mn> <mn>9</mn> </msup> </mrow> </math>   GeV for the linear and quadratic LIV models respectively. Our results obtained by using the flat  $$\Lambda $$  <math> <mi>Λ</mi> </math>  CDM model for characterizing the cosmic expansion history are consistent with those obtained using chronometers.

India

Shantanu Desai

Rajdeep Agrawal

Germany

Haveesh Singirikonda

Search for Lorentz invariance violation using Bayesian model comparison applied to Xiao et al. GRB spectral lag catalog

We suggest a minimal model for GeV-scale Majorana Dark Matter (DM) coupled to the standard model lepton sector via a charged scalar singlet. We show that there is an anti-correlation between the spin-independent DM-Nucleus scattering cross section (σ SI) and the DM relic density for parameters values allowed by various theoretical and experimental constraints. Moreover, we find that even when DM couplings are of order unity, σ SI is below the current experimental bound but above the neutrino floor. Furthermore, we show that the considered model can be probed at high energy lepton colliders using e.g. the mono-Higgs production and same-sign charged Higgs pair production.

South Korea

Adil Jueid

United Arab Emirates

Italy

Salah Nasri

Rachik Soualah

Searching for GeV-scale Majorana Dark Matter: inter spem et metum

Biswas et al. [1] found that the thermal relic density of a dark matter particle freezing out while the universe's energy density is dominated by a non-standard extra component ϕ, whose energy density redshifts faster than radiation, can be greatly suppressed. Here we show that this result, which contradicts extensive previous literature, is incorrect: the mistake lies with the assumption that the (decoupled) extra component ϕ contributes to the entropic degrees of freedom relevant for dark matter freeze out. If this were the case, a completely different approach would be needed to calculate the dark matter relic abundance, with dramatically different results.

United States

Nicolas Fernandez

Stefano Profumo

Comment on “keV neutrino dark matter in a fast expanding universe” by Biswas et al.

In 2016, we published “A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth’s gravity model. Measurement of Earth’s dragging of inertial frames [1]”, a measurement of frame-dragging, a fundamental prediction of Einstein’s theory of General Relativity, using the laser-ranged satellites LARES, LAGEOS and LAGEOS 2. The formal error, or precision, of our test was about 0.2% of frame-dragging, whereas the systematic error was estimated to be about 5%. In the 2017 paper “A comment on “A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth’s gravity model by I. Ciufolini et al.”” by L. Iorio [2] (called I2017 in the following), it was incorrectly claimed that, when comparing different Earth’s gravity field models, the systematic error in our test due to the Earth’s even zonal harmonics of degree 6, 8, 10 could be as large as 15%, 6% and 36%, respectively. Furthermore, I2017 contains other, also incorrect, claims about the number of necessary significant decimal digits of the coefficients used in our test (claimed to be nine), in order to eliminate the largest uncertainties in the even zonals of degree 2 and 4, and about the non-repeatability of our test. Here we analyze and rebut those claims in I2017.

Ignazio Ciufolini

Erricos Pavlis

John Ries

Richard Matzner

Rolf Koenig

Antonio Paolozzi

Giampiero Sindoni

Armenia

Vahe Gurzadyan

United Kingdom

Roger Penrose

Claudio Paris

Reply to “A comment on “A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model, by I. Ciufolini et al.””

We revisit charged lepton flavor violating (CLFV) scattering processes âiNâÏX(âiâe,Î¼) mediated by Higgs. We point out that a new subprocess âigâÏg via the effective interactions of Higgs and gluon gives the dominant contribution to âiNâÏX for an incident beam energy of Eââ²1Â TeV in fixed target experiments. Furthermore, in the light of quark number conservation, we consider quark pair-production processes âigâÏqqÂ¯ ( q denotes quarks) instead of âiqâÏq . This corrects the threshold energy of each subprocess contributing to Ï(âiNâÏX) . Reevaluation of Ï(âiNâÏX) including all of relevant subprocesses shows that the search for âiNâÏX could serve a complementary opportunity with other relevant processes to shed light on the Higgs CLFV.

Japan

Michihisa Takeuchi

Yuichi Uesaka

Masato Yamanaka

Higgs mediated CLFV processes μN ( eN )→ τX via gluon operators

Recently, Ciufolini et al. reported on a test of the general relativistic gravitomagnetic Lense–Thirring effect by analyzing about 3.5 years of laser ranging data to the LAGEOS, LAGEOS II, LARES geodetic satellites orbiting the Earth. By using the GRACE-based GGM05S Earth’s global gravity model and a linear combination of the nodes $$ \Omega $$ <math><mi>Ω</mi></math>  of the three satellites designed to remove the impact of errors in the first two even zonal harmonic coefficients $$J_2, J_4$$ <math><mrow><msub><mi>J</mi><mn>2</mn></msub><mo>,</mo><msub><mi>J</mi><mn>4</mn></msub></mrow></math>  of the multipolar expansion of the Newtonian part of the Earth’s gravitational potential, they claimed an overall accuracy of $${5}\%$$ <math><mrow><mn>5</mn><mo>%</mo></mrow></math>  for the Lense–Thirring caused node motion. We show that the scatter in the nominal values of the uncancelled even zonals of degree $$\ell = 6,~8,~{10}$$ <math><mrow><mi>ℓ</mi><mo>=</mo><mn>6</mn><mo>,</mo><mspace width="3.33333pt"></mspace><mn>8</mn><mo>,</mo><mspace width="3.33333pt"></mspace><mn>10</mn></mrow></math>  from some of the most recent global gravity models does not yet allow to reach unambiguously and univocally the expected $${\approx }1\%$$ <math><mrow><mo>≈</mo><mn>1</mn><mo>%</mo></mrow></math>  level, being large up to $${\lesssim }15\%~(\ell =6),~6\%~(\ell =8),~36\%~(\ell =10)$$ <math><mrow><mo>≲</mo><mn>15</mn><mo>%</mo><mspace width="3.33333pt"></mspace><mo>(</mo><mi>ℓ</mi><mo>=</mo><mn>6</mn><mo>)</mo><mo>,</mo><mspace width="3.33333pt"></mspace><mn>6</mn><mo>%</mo><mspace width="3.33333pt"></mspace><mo>(</mo><mi>ℓ</mi><mo>=</mo><mn>8</mn><mo>)</mo><mo>,</mo><mspace width="3.33333pt"></mspace><mn>36</mn><mo>%</mo><mspace width="3.33333pt"></mspace><mo>(</mo><mi>ℓ</mi><mo>=</mo><mn>10</mn><mo>)</mo></mrow></math>  for some pairs of models.

Lorenzo Iorio

A comment on “A test of general relativity using the LARES and LAGEOS satellites and a GRACE Earth gravity model”, by I. Ciufolini et al.

In a recent paper in EPJC January 2016, Faizal, Khalil and Das have proposed time crystals with duration several orders of magnitude greater than Planck scale. We comment on this paper and shed further light on this aspect.

B.G. Sidharth

Comment on Faizal et al EPJC 76:30

The discovery of a 125.5Â GeV Higgs with standard model-like couplings and naturalness considerations motivate gauge extensions of the MSSM. We analyse two variants of such an extension and carry out a phenomenological study of regions of the parameter space satisfying current direct and indirect constraints, employing state-of-the-art two-loop RGE evolution and GMSB boundary conditions. We find that due to the appearance of non-decoupled D-terms it is possible to obtain a 125.5Â GeV Higgs with stops below 2Â TeV, while the uncoloured sparticles could still lie within reach of the LHC. We compare the contributions of the stop sector and the non-decoupled D-terms to the Higgs mass, and study their effect on the Higgs couplings. We further investigate the nature of the next-to lightest supersymmetric particle, in light of the GMSB motivated searches currently being pursued by ATLAS and CMS.