arXiv subjects

Shraiyance Jain

Publications and source records attributed to Shraiyance Jain.

5 recordsLinked to original sources

arXiv2026

Multi-partite entanglement monotones

If we want to transform the quantum state of a system to another using local measurement processes, what is the probability of success? This probability is bounded by quantifying entanglement in both the states. In this paper, we construct a family of local unitary invariants of multipartite states that are monotonic under local operations and classical communication on average. These monotones are constructed from local unitary invariant polynomials of the state and its conjugate, and hence are easy to compute for pure states. Using these measures we bound the success probability of transforming a given state into another state using local quantum operations and classical communication.

quant-ph↗

arXiv2025

Monotones from multi-invariants: a classification

In this paper we study local unitary invariants of a multi-partite quantum state that are monotonic, on average, under local operations and classical communication (locc). In particular we focus on local unitary invariants that are constructed out of polynomials in the state and its conjugate - called multi-invariants. Multi-invariants are labeled by certain types of graphs. Recently, in \cite{Gadde:2024jfi}, the authors related the condition of monotonicity under locc to a graph theoretic condition on the multi-invariant called edge-convexity. In this paper, we conjecture a complete classification of edge-convex multi-invariants. The conjecture states that the edge-convex multi-invariants are labeled by finite Coxeter groups. We prove this conjecture for all but six cases.

quant-ph↗

arXiv2025

Analysis of s-t symmetric classical S-matrices

We analyze the complex analytic properties of Classical (tree-level) S-matrices for four scalar particles with s-t crossing symmetry, involving an infinite number of exchanges. Under suitable analytic conditions, we demonstrate that such S-matrices exhibit a spectrum of poles that is equally spaced. We extend this result to S-matrices with accumulating poles, proving that under analogous conditions, their pole spectrum coincides with that of the Coon S-matrix. The boundedness of the S-matrix in the Regge limit is not essential for our results. While studying S-matrices that do not meet the conditions of our theorems, we encounter functions that have novel non-isolated singularities akin to what is called the natural boundary.

hep-th↗

arXiv2023

Monotonicity conjecture for multi-party entanglement I

In this paper, we conjecture a monotonicity property that we call monotonicity under coarse-graining for a class of multi-partite entanglement measures. We check these properties by computing the measures for various types of states using different methods.

hep-th↗

arXiv2023

Bound on the central charge of CFTs in large dimension

In this paper, we use crossing symmetry and unitarity constraints to put a lower bound on the central charge of conformal field theories in large space-time dimensions $D$. Specifically, we work with the four-point function of identical scalars $ϕ$ with scaling dimension $Δ_ϕ$, and use a certain class of analytic functionals to show that the OPE coefficient squared $c^2_{ϕϕT^{μν}}$ must be exponentially small in $D$. For this to hold, we need to make a mild assumption about the nature of the spectrum below $2Δ_ϕ$. Our argument is robust and can be applied to any OPE coefficient squared $c^2_{ϕϕO}$ with $Δ_O< 2Δ_ϕ$. This suggests that conformal field theories in large dimensions (if they exist) must be exponentially close to generalized free field theories.

hep-th↗