arXiv subjects

Tanvi Krishnan

Publications and source records attributed to Tanvi Krishnan.

4 recordsLinked to original sources

arXiv2026

Sensitivity of the IceCube atmospheric muon rate to decadal trends in the effective atmospheric temperature

Decadal changes in the Antarctic stratosphere, generally associated with ozone recovery and shifts in polar circulation, are of broad geophysical interest. However, independent long-term measurements of the atmosphere above the Antarctic interior are scarce. We assess whether the atmospheric muon rate recorded by IceCube could constrain decadal changes in the effective atmospheric temperature, $T_\mathrm{eff}$, a weighted average of temperature through the atmosphere that is most sensitive to the stratosphere. Using public atmospheric reanalysis data and records of cosmic-ray, solar, and geomagnetic variability, we reproduce the measured seasonal response of the IceCube muon rate. We then test whether the same response applies to long-term temperature changes with a different vertical temperature profile. The limiting requirement is detector stability rather than counting statistics: an unmodeled muon rate drift of $1\%\,\mathrm{decade^{-1}}$ would mimic a temperature trend of $2.8\,\mathrm{K\,decade^{-1}}$. The long-term rate must therefore be stable to approximately $0.3\%\,\mathrm{decade^{-1}}$. Within this budget, snow accumulation contributions can be constrained. For a 14-year record, atmospheric variability gives a one-sided 95% CL statistical sensitivity of $1.6\,\mathrm{K\,decade^{-1}}$. Given this sensitivity, the $\sim0.9\,\mathrm{K\,decade^{-1}}$ cooling indicated by the 2011-2025 atmospheric records would become distinguishable after approximately 30 years of measurement.

hep-ph↗

arXiv2026

Scale-Invariant Open Quantum Systems

We develop a complete theoretical framework for open quantum systems coupled to scale-invariant environments. We show that such environments are universally described by unparticle baths characterized by a single scaling dimension $d_{\mathcal{U}}$. This work provides the proof of the uniqueness theorem, the formalism of the resulting non-Markovian dynamics, and applications to several physical systems. From the uniqueness theorem, we derive the non-Markovian memory kernels, the exact noise kernel including vacuum and thermal contributions, and a fractional generalization of the Caldeira-Leggett master equation for arbitrary $d_{\mathcal{U}}$. The scaling dimension governs a rich phase structure, including a thermalization transition at $d_{\mathcal{U}}=3/2$, the Ohmic boundary at $d_{\mathcal{U}}=2$, and a decoherence transition at $d_{\mathcal{U}}=5/2$ in the thermal regime, beyond which long-time quantum coherence is protected. Three realizations are studied. For the quantum Ising model at criticality, coupling to the energy operator in $(1+1)$ dimensions gives $d_{\mathcal{U}}=3/2$, producing $1/f$ noise, while the $(2+1)$D case yields $d_{\mathcal{U}}\approx1.413$ from the conformal bootstrap. In inflationary cosmology, massless scalar and graviton baths in de Sitter spacetime give $d_{\mathcal{U}}=2$, predicting linear decoherence growth consistent with the quantum-to-classical transition. For high-energy astrophysical neutrinos, the decoherence rate $Γ_{\mathrm{decoh}}\propto \mathcal{B}(E,T_{\mathcal{U}})L^{5-2d_{\mathcal{U}}}$ provides an observable signature of the scaling dimension. We also compare the framework with Caldeira-Leggett and Lindblad approaches, analyze the validity regimes, and discuss experimental implications for trapped-ion simulators, neutrino telescopes, and superconducting qubits.

hep-ph↗

arXiv2026

Universal Description of Decoherence in Scale-Invariant Environments

When a quantum system couples to a scale-invariant environment, what form must its decoherence take? We prove that the answer is unique: under locality, Lorentz invariance, unitarity, and continuous scale invariance, the effect of any such environment is mathematically equivalent to that of an \emph{unparticle bath} -- a scale-invariant continuum of states -- characterized entirely by the scaling dimension $d_{\mathcal{U}}$ of the coupled operator. This is not a modelling choice but a consequence of conformal symmetry. All decoherence and dissipation exponents are fixed by $d_{\mathcal{U}}$ through exact consistency relations, providing falsifiable predictions independent of microscopic details. We validate the framework using multi-channel transport data from the unitary Fermi gas, where two genuinely independent observables yield a consistent $d_{\mathcal{U}} = 7/4$. We further show that quantum Ising criticality, inflationary cosmology, and high-energy astrophysical neutrinos -- spanning more than 25 orders of magnitude in energy -- are unified as specific realizations of the same structure. A decoherence phase transition at $d_{\mathcal{U}} = 5/2$, where quantum coherence is \emph{protected} rather thandestroyed at long times, is a qualitative prediction inaccessible to any memoryless dynamical description.

hep-ph↗

arXiv2025

Search for Quantum Decoherence with 10.7 years of atmospheric $ν_μ$ events in IceCube

In order to develop a consistent quantum theory of gravity, we must understand the nature of spacetime at the Planck scale. In particular if it exhibits quantum fluctuations, they may cause propagating particles to evolve in an apparently non-unitary manner. Neutrinos, which interact only via the weak force and gravity, maintain quantum coherence while propagating over large distances. Thus, neutrino oscillations serve as a precise interferometer to search for Planck-scale fluctuations of spacetime. The IceCube Neutrino Observatory is the world's largest neutrino telescope, located in the Antarctic icecap. We search the data on atmospheric neutrinos detected by IceCube in the energy range 0.5-100 TeV to test for neutrino decoherence. In this contribution, we present the sensitivity of the analysis, which shows significant improvement compared to previous IceCube results as a result of improved reconstruction and a larger sample of events.

astro-ph.HE↗