Journal of Advanced Studies in Topology http://www.m-sciences.com/index.php?journal=jast <p style="text-align: justify;">The Journal of Advanced Studies in Topology (<strong>JAST</strong>) is dedicated to rapid publication of the highest quality short papers, regular papers, and expository papers.<span class="Apple-converted-space">&nbsp;</span><strong>JAST</strong><span class="Apple-converted-space">&nbsp;</span>is a peer-reviewed international journal, which publishes original research papers and survey articles in all aspects of topology and its applications.</p> Modern Science Publishers en-US Journal of Advanced Studies in Topology 2090-8288 <p>No manuscript should be submitted which has previously been published, or which has been simultaneously submitted for publication elsewhere. The copyright in a published article rests solely with the Modern Science Publishers, and the paper may not be reproduced in whole in part by any means whatsoever without prior written permission.</p> Semi-separation axioms on invertible and semi-invertible spaces http://www.m-sciences.com/index.php?journal=jast&page=article&op=view&path%5B%5D=1575 <p>In this paper we introduce the concept of semi-invertibility with respect to a semi-open set. Here we examine some semi-separation axioms which are carried from subspaces to parent spaces with the help of invertibility and semi-invertibility. Also we study these properties on completely invertible and completely semi-invertible spaces.</p> Neethu M Anjaly Jose Copyright (c) 2019 Modern Science Publishers http://creativecommons.org/licenses/by-nc/4.0 2019-10-03 2019-10-03 10 2 1 7 10.20454/jast.2019.1575 More on $$P$$-closed spaces http://www.m-sciences.com/index.php?journal=jast&page=article&op=view&path%5B%5D=1580 <p>In [1] the following problems were listed as open: Problem 14. Is a regular space in which every closed subset is regular-closed compact? Problem 15. Is a Urysohn-space in which every closed subset is Urysohnclosed compact? To answer the question for Hausdorff-closed spaces in the affirmative, M. H. Stone [12] used Boolean rings and M. Katˇetov [10] used topological methods. In this article, all three questions are answered affirmatively using filters.</p> Terrence A. Edwards James E. Joseph Bhamini M.P. Nayar Copyright (c) 2019 Modern Science Publishers http://creativecommons.org/licenses/by-nc/4.0 2019-11-09 2019-11-09 10 2 8 10 10.20454/jast.2019.1580 Some multi-valued contraction theorems on $$\mathcal{H}$$-cone metric http://www.m-sciences.com/index.php?journal=jast&page=article&op=view&path%5B%5D=1601 <p>In this paper we define some new type of multi-valued contraction maps on $$\mathcal{H}$$-cone metric and proved some fixed point and common fixed point theorems in the setting of cone metric spaces.</p> Saif Ur Rehman Shamoona Jabeenb Muhammad . Hayat Ullah Hanifullah . Copyright (c) 2019 Modern Science Publishers http://creativecommons.org/licenses/by-nc/4.0 2019-12-21 2019-12-21 10 2 11 24 10.20454/jast.2019.1601