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Showing 31 results for "prabhat" in Mathematics
Mathematics Preprint PDF DOI

The maximal order of the shifted-prime divisor function

Steve Fan, Paul Pollack ยท 2025

For each positive integer $n$, we denote by $\omega^*(n)$ the number of shifted-prime divisors $p-1$ of $n$, i.e., \[\omega^*(n):=\sum_{p-1\mid n}1.\] First introduced by Prachar in 1955, this functioโ€ฆ

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Cops and Robbers, Clique Covers, and Induced Cycles

Alexander Clow, Imed Zaguia ยท 2025

We consider the Cops and Robbers game played on finite simple graphs. In a graph $G$, the number of cops required to capture a robber in the Cops and Robbers game is denoted by $c(G)$. For all graphs โ€ฆ

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Efficient Tensor Decomposition via Moment Matrix Extension

Bobby Shi, Julia Lindberg, Joe Kileel ยท 2025

Motivated by a flurry of recent work on efficient tensor decomposition algorithms, we show that the celebrated moment matrix extension algorithm of Brachat, Comon, Mourrain, and Tsigaridas for symmetrโ€ฆ

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The Metric Dimension of Sparse Random Graphs

Josep Diaz, Harrison Hartle, Cristopher Moore ยท 2025

In 2013, Bollob\'as, Mitsche, and Pralat at gave upper and lower bounds for the likely metric dimension of random Erd\H{o}s-R\'enyi graphs $G(n,p)$ for a large range of expected degrees $d=pn$. Howeveโ€ฆ

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Modularity of preferential attachment graphs

Katarzyna Rybarczyk, Ma{l}gorzata Sulkowska ยท 2025

We study the preferential attachment model $G_n^h$. A graph $G_n^h$ is generated from a finite initial graph by adding new vertices one at a time. Each new vertex connects to $h\ge 1$ already existingโ€ฆ

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Mathematics Preprint PDF DOI

On products and partial isometry of Toeplitz operators with operator-valued symbols

Srijan Sarkar ยท 2024

We solve the following problems associated with Toeplitz operators $T_{\Phi}$ on Hilbert space-valued Hardy spaces $H_{\mathcal{E}}^2(\mathbb{D}^n)$ over the unit polydisc $\mathbb{D}^n$. $(I)$ Given โ€ฆ

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Coloring some $(P_6,C_4)$-free graphs with $\Delta-1$ colors

Ran Chen, Di Wu, Xiaowen Zhang ยท 2024

The Borodin-Kostochka Conjecture states that for a graph $G$, if $\Delta(G)\geq9$, then $\chi(G)\leq\max\{\Delta(G)-1,\omega(G)\}$. We use $P_t$ and $C_t$ to denote a path and a cycle on $t$ vertices,โ€ฆ

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Near Optimality of Lipschitz and Smooth Policies in Controlled Diffusions

Somnath Pradhan, Serdar Yuksel ยท 2024

For optimal control of diffusions under several criteria, due to computational or analytical reasons, many studies have a apriori assumed control policies to be Lipschitz or smooth, often with no rigoโ€ฆ

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Shifted-prime divisors

Steve Fan, Carl Pomerance ยท 2024

Let $\omega^*(n)$ denote the number of divisors of $n$ that are shifted primes, that is, the number of divisors of $n$ of the form $p-1$, with $p$ prime. Studied by Prachar in an influential paper froโ€ฆ

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A tight linear chromatic bound for ($P_3\cup P_2, W_4$)-free graphs

Rui Li, Jinfeng Li, Di Wu ยท 2023

For two vertex disjoint graphs $H$ and $F$, we use $H\cup F$ to denote the graph with vertex set $V(H)\cup V(F)$ and edge set $E(H)\cup E(F)$, and use $H+F$ to denote the graph with vertex set $V(H)\cโ€ฆ

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Borodin-Kostochka conjecture for a family of $P_6$-free graphs

Di Wu, Rong Wu ยท 2023

Borodin and Kostochka conjectured that every graph $G$ with $\Delta\ge9$ satisfies $\chi\le$ max $\{\omega, \Delta-1\}$. Gupta and Pradhan proved the Borodin-Kostochka conjecture for ($P_5$, $C_4$)-frโ€ฆ

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TOPress: a MATLAB implementation for topology optimization of structures subjected to design-dependent pressure loads

Prabhat Kumar ยท 2023

In a topology optimization setting, design-dependent fluidic pressure loads pose several challenges as their direction, magnitude, and location alter with topology evolution. This paper offers a compaโ€ฆ

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Stochastic Reservoir Calculations

Steven Finch ยท 2023

Prabhu (1958) obtained the stationary distribution of storage level $Z_{t}$ in a reservoir of finite volume $v$, given an inflow $X_{t}$ and an outflow $Y_{t}$. Time $t$ is assumed to be discrete, $X_โ€ฆ

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Almost all 9-regular graphs have a modulo-5 orientation

Michelle Delcourt, Reaz Huq, Pawel Pralat ยท 2022

In 1972 Tutte famously conjectured that every 4-edge-connected graph has a nowhere zero 3-flow; this is known to be equivalent to every 5-regular, 4-edge-connected graph having an edge orientation in โ€ฆ

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On a conjecture of R. M. Murty and V. K. Murty II

Yuchen Ding, Victor Zhenyu Guo, Yu Zhang ยท 2022

Let $\omega^*(n)$ be the number of primes $p$ such that $p-1$ divides $n$. Assuming the Elliott--Halberstam Conjecture, we prove a conjecture posted by M. R. Murty and V. K. Murty in 2021 which statesโ€ฆ

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Ramsey theory constructions from hypergraph matchings

Felix Joos, Dhruv Mubayi ยท 2022

We give asymptotically optimal constructions in generalized Ramsey theory using results about conflict-free hypergraph matchings. For example, we present an edge-coloring of $K_{n,n}$ with $2n/3 + o(nโ€ฆ

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Multi-source invasion percolation on the complete graph

Louigi Addario-Berry, Jordan Barrett ยท 2022

We consider invasion percolation on the randomly-weighted complete graph $K_n$, started from some number $k(n)$ of distinct source vertices. The outcome of the process is a forest consisting of $k(n)$โ€ฆ

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Hamilton cycles in a semi-random graph model

Alan Frieze, Gregory B. Sorkin ยท 2022

We show that with high probability we can build a Hamilton cycle after at most $1.85 n$ rounds in a particular semi-random model. In this model, in one round, we are given a {uniform random} $v\in[n]$โ€ฆ

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Normally torsion-free edge ideals of weighted oriented graphs

Gonzalo Grisalde, Jose Martinez-Bernal, Rafael H. Villarreal ยท 2021

Let $I=I(D)$ be the edge ideal of a weighted oriented graph $D$, let $G$ be the underlying graph of $D$, and let $I^{(n)}$ be the $n$-th symbolic power of $I$ defined using the minimal primes of $I$. โ€ฆ

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The jump of the clique chromatic number of random graphs

Lyuben Lichev, Dieter Mitsche, Lutz Warnke ยท 2021

The clique chromatic number of a graph is the smallest number of colors in a vertex coloring so that no maximal clique is monochromatic. In 2016 McDiarmid, Mitsche and Pralat noted that around p \apprโ€ฆ

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