arXiv subjects

Ayushi Srivastava

Publications and source records attributed to Ayushi Srivastava.

5 recordsLinked to original sources

arXiv2026

Towards a Proof of the Improved Quantum Null Energy Condition

The Improved Quantum Null Energy Condition (INEC) was recently derived from the (restricted) quantum focusing conjecture (QFC), and is a statement about the energy-momentum tensor (EMT) of field theories in Minkowski space-time. It extends the quantum null energy condition (QNEC), and includes the possibility of expanding or contracting geodesics. Treating the INEC as a field theory inequality, we use the properties of relative entropy and modular Hamiltonian associated with null deformation of the sphere to recast it as an integrated inequality. At leading order in a perturbation of the vacuum, this inequality becomes a weighted positivity condition on the smeared null energy. As the underlying single-segment light-cone operator is unbounded below for $d>2$, we pass to the Lorentzian cylinder $\mathbb{R}\times S^{d-1}$, where the operator is well-defined. We verify that the INEC holds explicitly in the thermal state, in both the perturbative and high-temperature regimes. Furthermore, using the QNEC and INEC as a basis, we briefly speculate about a possible modified Quantum Focusing Conjecture.

hep-th↗

arXiv2026

Slowly Rolling on a Quantum Correction

Recent advances in cosmological measurements such as DESI and ACT may indicate an increase in the preferred value of the spectral tilt $n_s$ such that it disfavors rather popular models such as the Higgs or Starobinski inflation models. We argue that it actually means that the data is now sensitive enough to quantum corrections beyond simple tree-level models. Resurrecting the old theme of Coleman-Weinberg effective potential, we analyze the predictions of such models, as well as likelihood analysis, leading to a more established and interesting predictive framework.

astro-ph.CO↗

arXiv2025

Islands in Bianchi type-I Universe

We study the conditions for finding an island in an anisotropic universe - Bianchi Type-I filled with radiation. We verify that the existence of islands does not depend on their shape. We then find that islands may form at certain times, near the turnaround point - where the universe turns from contraction to expansion in one of the directions. This is in line with previous analyses regarding cosmological space-times where islands form if one has two energy scales in the problem, such as the typical temperature of the universe and, on top of that, cosmological constant, curvature, anisotropy, or some mass scale.

hep-th↗

arXiv2023

Democratic three Higgs-doublet models: the custodial limit and wrong-sign Yukawa

We study two novel aspects of democratic 3HDMs -- the custodial limit and the possibility of wrong-sign Yukawa couplings. In the custodial limit, the democratic 3HDMs can easily negotiate the constraints from the electroweak $T$-parameter. We also uncover the possibility of having wrong-sign Yukawa couplings in democratic 3HDMs, as in the case of 2HDMs. We show that a democratic 3HDM encompasses all the wrong-sign possibilities entertained by 2HDMs, and has considerably more leeway in the wrong-sign limit as compared to the 2HDM case. Our study underscores the importance of reporting analysis in the kappa-formalism without any implicit assumptions on the signs of the kappas.

hep-ph↗

arXiv2022

Diluting quark flavor hierarchies using dihedral symmetry

We present a $D_4$ flavored extension of the SM which provides an intuitive reasoning for the masses and mixing patterns in the quark sector. In our model, the Cabibbo mixing angle stems purely from the scalar sector dynamics. In fact, the orders of magnitude of the CKM matrix elements are readily obtained from the hierarchical nature of the vacuum expectation values. Moreover, we also show that the smallness of the off-Cabibbo elements in the CKM matrix is strongly connected to the heaviness of the third generation of quarks.

hep-ph↗