Sambuddha Roy

Abstract We study some problems solvable in deterministic polynomial time given oracle access to thepromise version of the Arthur-Merlin class AM. The main result is that BPP (2009)

Merlin Oracles, Venkatesan T. Chakaravarthy, Sambuddha Roy

important property of the class PprAM| | is that it can be derandomized as PprAM| | = PNP| | , under a natural hardness hypothesis used for derandomizing the class AM; this directly follows from...

Approximating Maximum Weight K-Colorable Subgraphs in Chordal Graphs (2009)

Venkatesan T. Chakaravarthy, Sambuddha Roy

We present a 2-approximation algorithm for the problem of finding the maximum weight K-colorable subgraph in a given chordal graph with node weights. The running time of the algorithm is O(K(n+m)),...

Topology inside NC (2008)

Eric Allender, Sambuddha Roy

We show that ACC is precisely what can be computed with constant-width circuits of polynomial size and polylogarithmic genus. This extends a characterization given by Hansen, showing that planar...

DETERMINISTICALLY ISOLATING A PERFECT MATCHING IN BIPARTITE PLANAR GRAPHS (2008)

Samir Datta, Raghav Kulkarni, Sambuddha Roy

Abstract. We present a deterministic way of assigning small (log bit) weights to the edges of a bipartite planar graph so that the minimum weight perfect matching becomes unique. The isolation lemma...

Other (2008)

Sambuddha Roy

⋄ Prizes and Scholarships · 4th position in the IIT-Joint Entrance Exam, 1994, held all across India. · 1st position in the statewide Joint Entrance Exam, 1994, held in the state of West Bengal,...

EXP: the missing equivalence 1 Lowness of AM ∩ coAM (2008)

Sambuddha Roy

The fact that we will repeatedly use in the following is the result of [Sch89] that AM ∩ coAM exactly capture the low sets for AM. We do not have a similar nice result for MA- if we run through the...

Deterministically Isolating a Perfect Matching in Bipartite Planar Graphs (2008)

Datta, Samir, Kulkarni, Raghav, Roy, Sambuddha

We present a deterministic way of assigning small (log bit) weights to the edges of a bipartite planar graph so that the minimum weight perfect matching becomes unique. The isolation lemma as...

ABSTRACT Decision Trees for Entity Identification: Approximation Algorithms and Hardness Results (2008)

Venkatesan T, Vinayaka Pandit, Sambuddha Roy, Pranjal Awasthi, Mukesh Mohania

We consider the problem of constructing decision trees for entity identification from a given relational table. The input is a table containing information about a set of entities over a fixed set of...

Planar and Grid Graph Reachability Problems (2008)

Eric Allender, David A. Mix, Barrington Tanmoy, Chakraborty Samir Datta, Sambuddha Roy

We study the complexity of restricted versions of st-connectivity, which is the standard complete problem for NL. In particular, we focus on different classes of planar graphs, of which grid graphs...

Finding Irrefutable Certificates for $S_2^p$ via Arthur and Merlin (2008)

Chakaravarthy, Venkatesan, Roy, Sambuddha

We show that $S_2^p\subseteq P^{prAM}$, where $S_2^p$ is the symmetric alternation class and $prAM$ refers to the promise version of the Arthur-Merlin class $AM$. This is derived as a consequence of...

Deterministically Isolating a Perfect Matching in Bipartite Planar Graphs (2008)

Datta, Samir, Kulkarni, Raghav, Roy, Sambuddha

We present a deterministic way of assigning small (log bit) weights to the edges of a bipartite planar graph so that the minimum weight perfect matching becomes unique. The isolation lemma as...

Finding Irrefutable Certificates for $S_2^p$ via Arthur and Merlin (2008)

Chakaravarthy, Venkatesan, Roy, Sambuddha

We show that $S_2^p\subseteq P^{prAM}$, where $S_2^p$ is the symmetric alternation class and $prAM$ refers to the promise version of the Arthur-Merlin class $AM$. This is derived as a consequence of...

Deterministically Isolating a Perfect Matching in Bipartite Planar Graphs (2008)

Datta, Samir, Kulkarni, Raghav, Roy, Sambuddha

We present a deterministic way of assigning small (log bit) weights to the edges of a bipartite planar graph so that the minimum weight perfect matching becomes unique. The isolation lemma as...

15. Finding Irrefutable Certificates for S_2^p via Arthur and Merlin (2008)

Chakaravarthy, Venkatesan T., Roy, Sambuddha

We show that $S_2^psubseteq P^{prAM}$, where $S_2^p$ is the symmetric alternation class and $prAM$ refers to the promise version of the Arthur-Merlin class $AM$. This is derived as a consequence of...

21. Deterministically Isolating a Perfect Matching in Bipartite Planar Graphs (2008)

Datta, Samir, Kulkarni, Raghav, Roy, Sambuddha

We present a deterministic way of assigning small (log bit) weights to the edges of a bipartite planar graph so that the minimum weight perfect matching becomes unique. The isolation lemma as...

Rutgers University (2007)

Eric Allender, Distinguishing Complexity, Sambuddha Roy, Detlef Ronneburger

We continue an investigation of resource-bounded Kolmogorov complexity and derandomization techniques begun in [2, 3]. We introduce nondeterministic time-bounded Kolmogorov complexity measures (KNt...

Grid Graph Reachability Problems (2006)

Eric Allender, David A. Mix, Barrington Tanmoy, Chakraborty Samir Datta, Sambuddha Roy

We study the complexity of restricted versions of stconnectivity, which is the standard complete problem for NL. Grid graphs are a useful tool in this regard, since • reachability on grid graphs is...

Oblivious symmetric alternation (2006)

Venkatesan T. Chakaravarthy, Sambuddha Roy

1 Introduction The symmetric alternation class (Sp2) was introduced independently by Russelland Sundaram [16] and by Canetti [5]. The class S p 2 contains languages havingan interactive proof system...

Grid Graph Reachability Problems (2006)

Eric Allender, David A. Mix, Barrington Tanmoy, Chakraborty Samir Datta, Sambuddha Roy

We study the complexity of restricted versions of stconnectivity, which is the standard complete problem for NL. Grid graphs are a useful tool in this regard, since • reachability on grid graphs is...

Grid Graph Reachability Problems (2006)

Eric Allender, David A. Mix, Barrington Tanmoy, Chakraborty Samir Datta, Sambuddha Roy

We study the complexity of restricted versions of stconnectivity, which is the standard complete problem for NL. Grid graphs are a useful tool in this regard, since • reachability on grid graphs is...

A nonuniform lower bound for NEXP (2005)

Sambuddha Roy

We try to find the best lower bound for NEXP that we can get given current techniques. We extend the results in [BHY94] and in [FK05].

The directed planar reachability problem (2005)

Eric Allender, Samir Datta, Sambuddha Roy

Abstract. We investigate the s-t-connectivity problem for directed planar graphs, which is hard for L and is contained in NL but is not known to be complete. We show that this problem is...

The directed planar reachability problem (2005)

Eric Allender, Samir Datta, Sambuddha Roy

Abstract. We investigate the s-t-connectivity problem for directed planar graphs, which is hard for L and is contained in NL but is not known to be complete. We show that this problem is...

Time-space tradeoffs in the counting hierarchy (2001)

Eric Allender, Michal Kouck ´y, Detlef Ronneburger, Sambuddha Roy

We extend the lower bound techniques of [14], to the unbounded-error probabilistic model. A key step in the argument is a generalization of Nepomnjaˇsčiĭ’s theorem from the Boolean setting to...

Time-space tradeoffs in the counting hierarchy (2001)

Eric Allender, Michal Kouck ´y, Detlef Ronneburger, Sambuddha Roy, V Vinay

We extend the lower bound techniques of [17], to the unbounded-error probabilistic model. A key step in the argument is a generalization of Nepomnjaˇsčiĭ’s theorem from the Boolean setting to...