• Hana Salavcova participant image
  • Hana Salavcova
  • University: Charles University (Prague, Czech Republic)
  • Project Summary Page: 975 - Sensitive Sharing
  • Mentor: Arpita Biswas
  • Mentor Department: Computer Science
  • Project Site: https://archive.reu.dimacs.rutgers.edu/2025/hs1462/public_html
  • Project Site - Original: http://reu.dimacs.rutgers.edu/~hs1462
  • Personal Site: http://reu.dimacs.rutgers.edu/~hs1462/
  • Participant Year: 2025
  • Acknowlegements:

    I gratefully acknowledge the guidance of my supervisor Arpita Biswas throughout the course of this project.

    I would also like to thank the DIMACS REU 2025 program for providing me with this incredible research opportunity. I am especially grateful to Rutgers University and the DIMACS center for hosting the program and creating a stimulating and supportive research environment.

    This work is also partially supported by:

    • Department of Applied Mathematics
    • Informatics Institute of Charles University
    • RSJ Foundation
  • About Me:

    I am a third-year undergraduate student in Computer Science at Charles University in Prague, with a strong interest in theoretical computer science and applied mathematics. I am currently participating in a summer DIMACS REU research program in the United States.

  • Project Description:

    Title: Fair Allocation with Indivisible but Shareable Goods

    This project explores fairness in algorithmic game theory for settings with indivisible goods. We focus on a mild relaxation of indivisibility by allowing limited sharing of items among agents. Our goal is to revisit classical fairness notions under this new model, understand which of them can still be guaranteed, and investigate suitable algorithms and approximation techniques for computing fair allocations.

  • Weekly Log:
    Week 1 (May 27 - May 30)Log Description:
    • Read introductory materials on fair allocation problems
    • Initial meeting with mentor to discuss basics of fair allocation and possible research directions
    • Brainstormed new research idea and discussed possible settings and models with Martin to formalize the approach
    • Began outlining ideas for the initial presentation

    Literature

    • Amanatidis et al. (2023). Fair division of indivisible goods: Recent progress and open questions. [DOI]
    • Aziz et al. (2022). Algorithmic fair allocation of indivisible items: A survey and new questions. [DOI]
    Week 2 (June 2 - June 6)Log Description:
    • Finished preparing the initial presentation
    • Shared our Overleaf document and initial notes with our mentor
    • Held a short online meeting to discuss early ideas and feedback
    • Presented our initial presentation [view slides]
    • Significantly rewrote and reorganized our notes describing the shared setting (now with formal definitions and clearer structure)
    • Added basic proofs of fundamental properties of the model
    • Had an extended in-person meeting with our mentor to discuss various possible fairness notions (e.g., multiple variants of EFX, MMS)
    • Noted a connection between MMS in the cost-free setting and MMS in constrained settings

    Literature

    • Kurokawa, Procaccia, and Wang (2018). Fair Enough: Guaranteeing Approximate Maximin Shares. [DOI]
    • Anonymous (n.d.). Preprint manuscript, details withheld for confidentiality.
    • Chaudhury et al. (2021). A Little Charity Guarantees Almost Envy-Freeness. [DOI]
    Week 3 (June 9 - June 13)Log Description:
    • Updated the Overleaf template to make collaborative editing more structured and readable
    • Added new existential results for MMS and a preliminary result for EFX (which later turned out to be incorrect :( )
    • Attended the Tuesday seminar on mechanism design (mostly introductory, but engaging!)
    • Established a result connecting EFX across goods and chores
    • Met with our mentor on Thursday and agreed on formalization of the model and fairness notions
    • Reviewed and discussed our results related to SMMS and MMS — mentor was pleasantly surprised by our progress
    • Received detailed feedback on our Overleaf document (notation and further directions) and alredy addressed part of the comments and planned to revisit a specific result next week
    • Made initial progress on PROPx-related results
    • Participated in Friday's Culture Day, presented a Czech animal sound quiz (e.g., “chro chro”), enjoyed presentations and food!

    Literature

    • Feige, Sapir, and Tauber (2021). A tight negative example for MMS fair allocations. [DOI]
    • Guo et al. (2023). A Survey on Fair Allocation of Chores. [DOI]
    Week 4 (June 16 - June 19)Log Description:
    • Started with a stronger MMS/PROPx result expected to hold for all numbers of agents, but detailed proof showed it holds exactly only for even values of n, and only approximately for odd — the distinction turned out to be surprisingly insightful
    • Found a surprisingly good fit between MMS (bounding the number of items) and q-ary covering codes!
    • Dived into older covering code literature (mostly before 2011) and translated relevant results into our model
    • Joined the REU-wide pasta competition with homemade mushroom-pepper lasagna (fresh pasta included!)
    • Met with our mentor and discussed new ideas for PROPX, as well as new results for MMS
    • Considered preparing a paper focused on MMS and SMMS for submission to WINE 2025 (discussed directions for the write-up)

    Literature

    • Haas et al. (2009). Lower Bounds forq-ary Codeswith Large Covering Radius. [DOI]
    • Gijswijt and Polak (2025). Semidefinite lower bounds for covering codes. [DOI]
    Week 5 (June 23 - June 27)Log Description:
    • Finalized a draft of our paper — polished proofs, formalized results, and refined the overall structure and exposition
    • Learned from our mentor about a newly published paper with significant overlap
    • Reviewed the preprint and confirmed that much of our work was already covered
    • Decided not to submit the current paper and shifted focus to new, unexplored directions suggested by the uncovered gaps

    Literature

    • Barman et al. (2025). Exact Maximin Share Fairness via Adjusted Supply. [DOI]
    • Brederek et al. (2023). Improving Resource Allocations by Sharing in Pairs. [DOI]
    Week 6 (June 30 - July 3)Log Description:
    • Derived new bounds on SMMS in various models, and bounds on MMS and SMMS using full-sharing SMMS
    • Used known approximation results for CMMS to obtain new approximations for MMS and SMMS
    • Studied in more depth the recent paper discovered last week and analyzed its probabilistic approach
    • Adapted a similar probabilistic technique to prove a new theoretical result approximating MMS
    • Explored a weighted version of MMS for the weighted-cost setting, but observed unintuitive behavior on examples and decided to drop this direction
    Week 7 (July 7 - July 11)Log Description:
    • Shifted focus toward the algorithmic side — reviewed existing algorithms, most of which failed or gave weak guarantees in the shared setting
    • Successfully adapted the Bag-Filling algorithm to improve MMS approximations in equal-share models
    • Generalized the new algorithm to arbitrary cost models, leading to exact MMS under milder conditions than before
    • Started preparing a polished write-up of our results (now both theoretical and algorithmic!)
    • Identified a new conference where we may present our framework for shared fair allocation — fingers crossed this time!

    Literature

    Amanatidis et al. (2023). Fair Division of Indivisible Goods: Recent Progress and Open Questions. [DOI]
    Garg et al. (2019). Approximating Maximin Share Allocations. [DOI]