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We analyse the longitudinal variability of solar tidal amplitudes using hourly recordings of the horizontal (H) component from ground magnetic observatories at Guam (GUA, dip latitude: ∼6.0°N), Hyderabad (HYB, dip latitude: ∼10.5°N), and Alibag (ABG, dip latitude: ∼13.0°N), along with solar activity index (√F10.7) and the revised Disturbance storm time (Dst) index during the 22nd solar cycle (1986-1996). This period represents a distinct transitional phase in solar variability, characterized by strong and symmetric activity that exhibited a 'double-peak' behavior. This feature was less pronounced in cycles 21st and 23rd, and the 22nd cycle also showed a comparatively high sunspot maximum accompanied by enhanced geomagnetic disturbances. Consequently, it serves as a useful reference point for understanding the longitudinal variability of solar tidal signatures on the geomagnetic field, including: diurnal (S1), semi-diurnal (S2), ter-diurnal (S3), and quatra-diurnal (S4) components throughout different phases of the solar cycle. Our findings reveal that GUA has the highest solar quiet (Sq) amplitudes across all tidal modes (S1-S4) during all the seasons, and the tidal amplitudes decrease from east (GUA) to west (ABG) over the course of the solar cycle. Additionally, there are strong correlations between √F10.7 and S1 at the observatories, S2 also shows a strong relationship, except at ABG during the maximum phase. S3 demonstrates a negative correlation during minimum phases across all sites. A moderate correlation is observed for S4 at GUA, with weaker correlations at HYB and ABG. Highlighting these differences are essential for understanding the minimum spatial extent of each tide, along with their associated annual and semi-annual characteristics at various longitudinal intervals. The observed longitudinal variability in solar tides, even at 05° (HYB and ABG), highlights the role of various factors such as wave sources, propagation conditions, local planetary and gravity waves, and differences in conductivity on variations in the geomagnetic field.

The only two gauge symmetries which remain unbroken today are SU(3)<SUB> c </SUB> and U(1)<SUB>EM</SUB>. Both are crucial for our universe to appear the way it does and for our form of life to exist. Unless we are very special observers living at the very end of the cosmological symmetry-breaking chain, there is no reason to believe that these two symmetries will remain unbroken forever. In this paper, we investigate the cosmological observational signatures of a late-time SU(3)<SUB> c </SUB> symmetry breaking. We introduce a model with a new colored scalar field whose potential supports a first-order phase transition through nucleation of true-vacuum bubbles. We analyze three physically distinct particle-production mechanisms associated with the expanding bubble wall. The first is direct nonthermal particle production from vacuum mismatch across the accelerating wall, including both the scalar and massive-gluon sectors. The second is particle production from frictional dissipation into a shocked layer. For this channel we include the finite-temperature effective potential and show that, for our benchmark, the critical temperature is below the massive-gluon and scalar masses; therefore an equilibrated relativistic thermal bath of broken-phase massive particles would restore SU(3)<SUB> c </SUB>. We consequently formulate a subcritical thermal freeze-out estimate below T<SUB>c</SUB> , where massive broken-phase particles can still be produced but only with Boltzmann suppression. The third is a non-equilibrium wall-matter transition-radiation channel, in which ambient baryonic matter crossing the relativistic SU(3)<SUB> c </SUB> → U(2) wall can radiate broken-phase massive gluons and scalar excitations. This channel does not require a thermal bath above T<SUB>c</SUB> and can continue after the wall reaches terminal velocity. We then study the decays of the physical color-octet scalar and the massive gluons, and use Pythia to hadronize their decay products and determine the resulting photon and neutrino spectra. If the wall reaches a subluminal terminal velocity, these photons and neutrinos can arrive before the wall itself. The resulting high-energy photon and neutrino spectra constitute a long-range observational signature which, if ever observed, could be interpreted as a signal of cosmic doomsday.

We present ABCMB, a differentiable Einstein-Boltzmann solver for the cosmic microwave background (CMB). ABCMB is an analysis-ready code package capturing important effects to linear order in ΛCDM cosmology. It computes the CMB power spectrum and includes effects like lensing, polarization, massive neutrinos, and a state-of-the-art treatment of Big Bang Nucleosynthesis and recombination. ABCMB has sub-percent-level agreement with CLASS and can be run on a GPU with competitive, and sometimes even faster, run times, owing to ABCMB's favorable run time scaling with maximum multipole moment. It is refactored compared to previous codes and takes advantage of object-oriented programming to improve extensibility, meaning new physics can be added to it without the need for modifying source files. ABCMB provides accurate and stable gradients to the user, making Fisher analyses straightforward, and enabling the use of efficient gradient-based sampling methods.