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While the simplest inflationary models predict a power-law form of the primordial power spectrum (PPS), various UV complete scenarios predict features on top of the standard power law that leave characteristic imprints in the late-time distribution of matter, encoded in the galaxy power spectrum. In this work, we assess the validity of the Effective Field Theory of Large Scale Structure (EFTofLSS) and the IR-resummation scheme of PyBird in the context of primordial (oscillatory) features. We find an excellent agreement at the level of the matter power spectrum between N-body simulations and the one-loop EFT predictions, for models commonly studied in the literature. We then apply the EFTofLSS to the galaxy power spectrum measurements from BOSS LRG and eBOSS QSO to constrain specific global and local features in the PPS. We demonstrate that while such features can improve the fit to cosmic microwave background (CMB) data, they may result in a poorer fit to clustering measurements at low redshift. The resulting constraints on the amplitude of the primordial oscillations are competitive with those obtained from CMB data, despite the well-known damping of oscillations due to non-linear structure formation processes. For the first time in this context, we jointly analyze the galaxy power spectrum (monopole and quadrupole) in combination with Planck CMB data to derive strong constraints on the amplitude of primordial features. This work highlights the EFTofLSS as a powerful tool for testing early universe scenarios on scales that complement CMB observations.
This study probes spacetime solutions within Einstein-Bumblebee gravity, a modified gravitational framework incorporating spontaneous Lorentz symmetry violation through a vector field mechanism. By introducing a cosmological constant into this model, the research scrutinizes thermodynamic properties of black holes in both anti-de Sitter (AdS) and de Sitter (dS) geometries. The investigation demonstrates how Lorentz-violating parameters alter foundational thermodynamic principles, including revisions to the first law of black hole mechanics and shifts in critical phenomena during phase transitions. Notably, the bumblebee coupling parameter emerges as a critical factor governing horizon structure and thermal emission characteristics, with pronounced deviations from general relativity (GR) predictions observed as this parameter increases. The analysis extends to observational signatures by calculating shadow profiles of these modified black holes. Shadow morphology exhibits dual dependence on the cosmological constant and the bumblebee parameter, presenting measurable discrepancies from classical relativity that could be constrained through Event Horizon Telescope (EHT) observational data. Furthermore, using geometric formalisms, the study quantifies light deflection phenomena in weak and strong gravitational regimes. Results reveal that both the cosmological constant and Lorentz-violating parameter induce detectable modifications to lensing angles compared to Schwarzschild or Kerr benchmarks. These deviations, while subtle, underscore the necessity for next-generation astronomical instruments capable of resolving fine-scale spacetime curvature effects.
KMOC (Kosower, Maybee, and O’Connell) formalism is an approach to analyze classical scattering in gauge theories and gravity using a class of “inclusive” observables which can be computed solely from on-shell amplitudes [JHEP 02 (2019) 137]. This formalism has led to striking developments in the context of perturbative scattering, which corresponds to large impact parameter scattering. As a result, in its current form, the KMOC formulae cannot be directly applied to processes for generic values of the impact parameter. However, there is a domain where the relationship between classical radiation and on-shell amplitudes can be stretched beyond large impact parameter scattering. This regime is defined by the soft expansion of outgoing radiation. It is thus natural to ask whether such soft radiative fields can be computed using the basic paradigm set by the KMOC formalism. In this short note, we show that this is indeed the case for electromagnetic memory. In particular, we compute an inclusive observable associated with soft flux at ℐ^+ and show that, irrespective of the details of the hard scattering, this observable defines a non-perturbative formula for the electromagnetic memory in the classical limit. We argue that the result obtained for electromagnetic memory using the KMOC paradigm is consistent with that of [JHEP 09 (2018) 105], where the classical limit of the quantum soft theorem was derived using saddle-point analysis. The gravitational case, however, is qualitatively different due to the presence of the nonlinear memory effect, which requires knowledge of the hard amplitude. Consequently, unlike the electromagnetic memory, we have not been able to show consistency of the leading soft graviton theorem and the soft inclusive gravitational flux obtained using the KMOC formalism.
Abstract We investigate the phenomenological prospects of the Two Higgs Doublet and Complex Singlet Scalar Extension (2HDMS) in the context of dark matter (DM) and Higgs phenomenology. The 2HDMS provides an enlarged Higgs sector along with a DM candidate. In this work, we perform an exhaustive scan to find representative benchmarks which are consistent with all theoretical and experimental constraints. We choose benchmarks with light, intermediate and massive DM masses and in some cases, also accommodate the 95 GeV excess in $$b\bar{b}$$ b b ¯ and $$\gamma \gamma $$ γ γ channels observed at the Large Electron-Positron Collider (LEP) and Large Hadron Collider (LHC). We investigate and compare different DM signal topologies for different DM mass regions and focus on the relevant signatures at all current and future colliders such as the LHC and at proposed future lepton colliders including electron-positron and muon colliders. Using a cut and count analysis, we show that while the High Luminosity LHC (HL-LHC) may hint towards new physics, future lepton colliders prove to be efficient discovery probes for DM searches at colliders.
We study the lepton flavour conserving and violating couplings of a doubly charged scalar at a 3 TeV muon collider. Using a model independent Lagrangian, we analyse the electron electron, muon muon, and tau tau final states mediated by the doubly charged scalar to probe individual couplings to mu e, mu mu, and mu tau. We find that for a doubly charged scalar of mass greater than 1 TeV and order one couplings, we achieve high signal significance in these channels. We delineate the collider s sensitivity in the mass vs coupling plane, highlighting the extensive reach of the muon collider in probing these couplings far beyond the current experimental limits. We also propose an angular distribution variable to discriminate the exchange of a doubly charged scalar from that of a neutral scalar, which give identical signals.
