activity
20112025
most citedThe Bar-Natan homology and unknotting number

21 citations · 59 across the 15 of their papers we have counts for

collaborators

16 papers

math.GT2025

Colored knot Floer homology: structures and examples

Akram Alishahi, Eugene Gorsky, Beibei Liu

Inspired by the colored version of Khovanov and Khovanov-Rozansky homology, we define a colored version of knot Floer homology by studying the colimit of a directed system of…

math.GT2025

Detecting Heegaard Floer homology solid tori

Akram Alishahi, Tye Lidman, Robert Lipshitz

We show that a rational homology solid torus is a Heegaard Floer homology solid torus if and only if it has a Dehn filling with a non-separating 2-sphere. Using this, we characteri…

math.GT2024

Bordered Floer homology, handlebody detection, and compressing diffeomorphisms

Akram Alishahi, Robert Lipshitz

We show that, up to connected sums with integer homology -spaces, bordered Floer homology detects handlebodies, as well as whether a mapping class extends over a given handlebod…

math.GT2023★ 2 cited

Splitting maps in link Floer homology and integer points in permutahedra

Akram Alishahi, Eugene Gorsky, Beibei Liu

In this paper, we study the skein exact sequence for links via the exact surgery triangle of link Floer homology and compare it with other skein exact sequences given by Ozsváth an…

math.GT2023

Khovanov homology and the Involutive Heegaard Floer homology of branched double covers

Akram Alishahi, Linh Truong, Melissa Zhang

We use involutive Heegaard Floer homology to extend the Ozsváth-Szabó branched double cover spectral sequence relating a version of Khovanov homology and the Heegaard Floer homolog…

math.GT2022

Upsilon invariant for graphs and the homology cobordism group of homology cylinders

Akram Alishahi

Upsilon is a homomorphism on the smooth concordance group of knots defined by Ozsváth, Stipsicz and Szabó. In this paper, we define a generalization of upsilon for a family of embe…

math.GT2021★ 1 cited

A friendly introduction to the bordered contact invariant

Akram Alishahi, Joan Licata, Ina Petkova +1

We give a short introduction to the contact invariant in bordered Floer homology defined by Földvári, Hendricks, and the authors. The construction relies on a special class of foli…

math.GT2020★ 2 cited

Bordered Floer homology and contact structures

Akram Alishahi, Viktória Földvári, Kristen Hendricks +3

We introduce a contact invariant in the bordered sutured Heegaard Floer homology of a three-manifold with boundary. The input for the invariant is a contact manifold $(M, ξ, \mathc…

math.GT2019★ 1 cited

Relating tangle invariants for Khovanov homology and knot Floer homology

Akram Alishahi, Nathan Dowlin

Ozsvath and Szabo recently constructed an algebraically defined invariant of tangles which takes the form of a DA bimodule. This invariant is expected to compute knot Floer homolog…

math.GT2018★ 1 cited

A link invariant related to Khovanov homology and knot Floer homology

Akram Alishahi, Nathan Dowlin

In this paper we introduce a chain complex where D is a plat braid diagram for a knot K. This complex is inspired by knot Floer homology, but it the construction i…

math.GT2018★ 13 cited

Knot Floer homology and the unknotting number

Akram Alishahi, Eaman Eftekhary

Given a knot K in S^3, let u^-(K) (respectively, u^+(K)) denote the minimum number of negative (respectively, positive) crossing changes among all unknotting sequences for K. We us…

math.GT2017★ 1 cited

The Lee Spectral Sequence, Unknotting Number, and the Knight Move Conjecture

Akram Alishahi, Nathan Dowlin

We show that the page at which the Lee spectral sequence collapses gives a bound on the unknotting number, u(K). In particular, for knots with u(K)<3, we show that the Lee spectral…

math.GT2017★ 21 cited

The Bar-Natan homology and unknotting number

Akram Alishahi

We show that the order of torsion homology classes in Bar-Natan deformation of Khovanov homology is a lower bound for the unknotting number. We give examples of knots that this is…

math.GT2017★ 11 cited

Bordered Floer homology and incompressible surfaces

Akram Alishahi, Robert Lipshitz

We show that bordered Heegaard Floer homology detects incompressible surfaces and bordered-sutured Floer homology detects partly boundary parallel tangles and bridges, in natural w…

math.GT2016★ 6 cited

Tangle Floer homology and cobordisms between tangles

Akram Alishahi, Eaman Eftekhary

We introduce a generalization of oriented tangles, which are still called tangles, so that they are in one-to-one correspondence with the sutured manifolds. We define cobordisms be…

math.GT2011

A refinement of sutured Floer homology

Akram S. Alishahi, Eaman Eftekhary

We introduce a refinement of the Ozsvath-Szabo complex associated to a balanced sutured manifold by Juhasz. An algebra is associated to the boundary of a sutured mani…