Professor
Mathematical Sciences
Office
Marcus White Hall
111
Monday
8:50 am - 9:20 am
1:30 pm - 2:40 pm
Wednesday
8:50 am - 9:20 am
1:30 pm - 2:40 pm
Friday
8:50 am - 9:20 am
1:30 pm - 2:40 pm
Or by appointment
Education
Mathematics/Topology
Sofia University, Sofia, Bulgaria
1989
Mathematics/Topology
Sofia University, Sofia, Bulgaria
1984
Mathematics and Computer Science
Sofia University, Sofia, Bulgaria
1982
Areas of Expertise
  1. General, Categorical, and Geometric Topology and their Applications
    Product spaces; continuous extensions of functions defined on subspaces of product spaces; cardinal invariants; covering properties; compact, pseudocompact, countable compact and sequentially compact spaces; closure operators; P-minimal and P-closed spaces; sequential convergence; sequential spaces; extensions of topological spaces; supertopological spaces; neighborhood spaces; separation axioms; proximities; Noetherian spaces; applications of topology in number theory and geographic information systems.
  2. Graph Theory
    Hamiltonian graphs
Publications, Research & Presentations
  • Publications in peer-reviewed journals

    1.  Superneighborhood spaces and extensions of topological spaces,  80 (1986), no. 1, 31 – 43.
    2. Sequentially closed and absolutely closed spaces, Boll. Un. Mat. Ital. B(7) 1 (1987), no. 3, 849 – 860.
      Co-author: D. Dikranjan
    3. Topological spaces with no compactly determined extensions, , Sunny Beach, Bulgaria, April 6-9, (1988), 151 – 155.
    4. Sequentially P-closed spaces,  20 (1988), no. 1, 1 – 17.
       (The original publication is available via .)
    5. On sequential properties of Noetherian topological spaces, Topology Proc. 28 (2004), No. 2, 487 – 501.
      Co-author: H. Minchev
       (The original publication is available via http://www.topology.auburn.edu/tp/reprints/v28/tp28210.pdf.)
    6. Dense C-embedded subspaces of products,  64 (2006), No. 3, 509 – 515.
      Co-authors: W. W. Comfort and L. Recoder-Núñez
       (The original publication is available via .)
    7. M-embedded subspaces of certain product spaces, Topology Appl. 155 (2008), No. 17-18, 2188 – 2195.
      Co-authors: W. W. Comfort and L. Recoder-Núñez
       (The original publication is available via .)
    8. On the continuity of factorizations,  9 (2008), No. 2, 263 – 280.
      Co-authors: W. W. Comfort and L. Recoder-Núñez
       (The original publication is available via .)
    9. Functional dependence on small sets of indices,  69 (2009), No. 3, 363 – 377.
      Co-author: W. W. Comfort
       (The original publication is available via .)
    10. Continuous mappings on subspaces of products with the κ-box topology, Topology Appl. 156 (2009), No. 16, 2600 – 2608.
      Co-author: W. W. Comfort
       (The original publication is available via .)
    11. On two conjectures about faulty hypercubes,  LVII (2009), 34 – 38.
      Co-authors: N. Castañeda, , F. Latour
    12. Path coverings with prescribed ends of the n-dimensional binary hypercube, Congr. Numer. 197 (2009), 193 – 205.
      Co-authors: N. Castañeda, , F. Latour
    13. Hamiltonian laceability of hypercubes with faults of charge one, Congr. Numer. 198 (2009), 15 – 30.
      Co-authors: N. Castañeda, , F. Latour
    14. On k-semi-perfect 1-factorizations of Qn and Craft's conjecture,  LVIII (2010), 36 – 41.
      Co-author: 
    15. On path coverings of hypercubes with one faulty vertex,  LVIII (2010), 42 – 47.
      Co-authors: N. Castañeda, , F. Latour
    16. Embedded paths and cycles in faulty hypercubes,  20 (2010), No. 3, 224 – 248.
      Co-author: N. Castañeda
       (The original publication is available at Springer via .)
    17. Classifying simple closed curve pairs on the 2-sphere and a generalization of the Schoenflies theorem, Topology Appl. 158 (2011), No. 6, 748 – 760.
      Co-authors: R. Franzosa and 
       (The original publication is available via .)
    18. Continuous extensions of functions defined on subsets of products, Topology Appl. 159 (2012), No. 9, 2331 – 2337.
      Co-author: W. W. Comfort
       (The original publication is available via .)
    19. Continuous extensions of functions defined on subsets of products with the κ-box topology,  42 (2013), 209 – 219.
      Co-authors: W. W. Comfort and D. Rivers
       (The original publication is available via http://www.topology.auburn.edu/tp/reprints/v42/tp42017.pdf.)
    20. The non-Hausdorff number of a topological space,  44 (2014), 249 – 256.
       (The original publication is available via http://www.topology.auburn.edu/tp/restricted/v44/tp44022.pdf.)
    21. Path coverings with prescribed ends in faulty hypercubes,  31 (2015), 833 – 869.
      Co-author: N. Castañeda
       (The original publication is available at Springer via .)
    22. Regular Gδ-diagonals and some upper bounds for cardinality of topological spaces,  149 (2016), No. 2, 324 – 337.
      Co-authors: M. Tkachenko and V. Tkachuk
      (The original publication is available at Springer via .)
    23. Cardinal invariants for κ-box products: weight, density character and Souslin number,  516 (2016), 1 – 41.
      Co-author: W. W. Comfort
      (The original publication is available via .)
    24. The non-Urysohn number of a topological space,  43 (2017), No. 1, 223 – 235.
      (The original publication is available via .)
    25. Generalizations of two cardinal inequalities of Hajnal and Juhász,  221 (2017), 425 – 431.
      (The original publication is available via .)
    26. Proof of Locke's conjecture, I,  6 (2017), No. 2, 345 – 371.
      Co-author: N. Castañeda
      (The original publication is available via .)
    27. Cardinal inequalities for Urysohn spaces involving variations of the almost Lindelöf degree,  44 (2018), 195 – 212.
      (The original publication is available via .)
    28. More on the cardinality of S(n)-spaces,  44 (2018), 227 – 242.
      Co-author: L. KoÄinac
      (The original publication is available via .)
    29. Cardinalities of weakly Lindelöf spaces with regular G_κ-diagonals,  259 (2019), 80 – 89.
      (The original publication is available via .)
    30. Cardinal inequalities for S(n)-spaces,  159 (2019), No. 1, 229 – 245.
      (The original publication is available at Springer via .)
    31. Cardinal inequalities with Shanin number and π-character, 29 (2022), no. 3, 389 – 403.
      Co-author: V. Tkachuk
      (The original publication is available at Project Euclid via .)
    32. More on cardinality bounds involving the weak Lindelöf degree, 46 (2023), no. 4, 745 – 760.
      Co-authors:   and 
      (The original publication is available via .)
    33. On the upper bound of the cardinality of Hausdorff topological spaces, , 338 (2023), Article 108651.
      (The original publication is available via  .)
    34. On spaces with a Ï€-base with elements with compact closure,  118 (2024), no. 1, article 26.
      Co-authors:   and   
      (The original publication is available via  .)
       

     Submitted or Accepted for Publication

    1.  Strengthening of de Groot’s and Spadaro’s inequalities for Urysohn spaces (submitted for publication).
       

     Work in Progress

    1.  Proof of Locke's conjecture, II (preprint).
      Co-authors: N. Castañeda, , F. Latour
    2. On the infinitude of prime divisors of the range of a non-constant polynomial (preprint).
Memberships & Affiliations

American Mathematical Society (AMS)

Mathematical Association of America (MAA)

Courses Taught

Spring 2025

MWF 9:25 am - 10:35 am - , EDB 111

MWF 10:50 am - 12:00 pm - , EDB 111

MWF 12:15 pm - 1:25 pm - , EDB 111

for Calculus I (section 03)

for Calculus I (section 03)

for Calculus I (section 03)

for Calculus I (section 03)

for Calculus II (sections 04 and 06)

for Calculus II (sections 04 and 06)

for Calculus II (sections 04 and 06)

for Calculus II (sections 04 and 06)

Office Hours Spring 2025

MWF 8:50 am - 9:20 am in MW 111

MWF 1:30 pm - 2:40 pm in MW 111

or by appointment