Research article

Some properties of a new subclass of tilted star-like functions with respect to symmetric conjugate points

  • In this paper, we introduced a new subclass SSC(α,δ,A,B) of tilted star-like functions with respect to symmetric conjugate points in an open unit disk and obtained some of its basic properties. The estimation of the Taylor-Maclaurin coefficients, the Hankel determinant, Fekete-Szegö inequality, and distortion and growth bounds for functions in this new subclass were investigated. A number of new or known results were presented to follow upon specializing in the parameters involved in our main results.

    Citation: Daud Mohamad, Nur Hazwani Aqilah Abdul Wahid, Nurfatin Nabilah Md Fauzi. Some properties of a new subclass of tilted star-like functions with respect to symmetric conjugate points[J]. AIMS Mathematics, 2023, 8(1): 1889-1900. doi: 10.3934/math.2023097

    Related Papers:

    [1] Maria Parapouli, Anastasios Vasileiadis, Amalia-Sofia Afendra, Efstathios Hatziloukas . Saccharomyces cerevisiae and its industrial applications. AIMS Microbiology, 2020, 6(1): 1-31. doi: 10.3934/microbiol.2020001
    [2] Alfred Mitema, Naser Aliye Feto . Molecular and Vegetative Compatibility Groups Characterization of Aspergillus flavus Isolates from Kenya. AIMS Microbiology, 2020, 6(3): 231-249. doi: 10.3934/microbiol.2020015
    [3] Bambang Irawan, Aandi Saputra, Salman Farisi, Yulianty Yulianty, Sri Wahyuningsih, Noviany Noviany, Yandri Yandri, Sutopo Hadi . The use of cellulolytic Aspergillus sp. inoculum to improve the quality of Pineapple compost. AIMS Microbiology, 2023, 9(1): 41-54. doi: 10.3934/microbiol.2023003
    [4] Mohammed M. M. Abdelrahem, Mohamed E. Abouelela, Nageh F. Abo-Dahab, Abdallah M. A. Hassane . Aspergillus-Penicillium co-culture: An investigation of bioagents for controlling Fusarium proliferatum-induced basal rot in onion. AIMS Microbiology, 2024, 10(4): 1024-1051. doi: 10.3934/microbiol.2024044
    [5] Oluwafolajimi Adesanya, Tolulope Oduselu, Oluwawapelumi Akin-Ajani, Olubusuyi M. Adewumi, Olusegun G. Ademowo . An exegesis of bacteriophage therapy: An emerging player in the fight against anti-microbial resistance. AIMS Microbiology, 2020, 6(3): 204-230. doi: 10.3934/microbiol.2020014
    [6] Nur Raihan Abdullah, Faez Sharif, Nur Hafizah Azizan, Ismail Fitri Mohd Hafidz, Sugenendran Supramani, Siti Rokhiyah Ahmad Usuldin, Rahayu Ahmad, Wan Abd Al Qadr Imad Wan-Mohtar . Pellet diameter of Ganoderma lucidum in a repeated-batch fermentation for the trio total production of biomass-exopolysaccharide-endopolysaccharide and its anti-oral cancer beta-glucan response. AIMS Microbiology, 2020, 6(4): 379-400. doi: 10.3934/microbiol.2020023
    [7] Bahram Nikmanesh, Kazem Ahmadikia, Muhammad Ibrahim Getso, Sanaz Aghaei Gharehbolagh, Shima Aboutalebian, Hossein Mirhendi, Shahram Mahmoudi . Candida africana and Candida dubliniensis as causes of pediatric candiduria: A study using HWP1 gene size polymorphism. AIMS Microbiology, 2020, 6(3): 272-279. doi: 10.3934/microbiol.2020017
    [8] Hafidh Shofwan Maajid, Nurliyani Nurliyani, Widodo Widodo . Exopolysaccharide production in fermented milk using Lactobacillus casei strains AP and AG. AIMS Microbiology, 2022, 8(2): 138-152. doi: 10.3934/microbiol.2022012
    [9] Chika C. Anotaenwere, Omoanghe S. Isikhuemhen, Peter A. Dele, Michael Wuaku, Joel O. Alabi, Oludotun O. Adelusi, Deborah O. Okedoyin, Kelechi A. Ike, DeAndrea Gray, Ahmed E. Kholif, Uchenna Y. Anele . Ensiled Pleurotus ostreatus based spent mushroom substrate from corn: In vitro gas production, greenhouse gas emissions, nutrient degradation, and ruminal fermentation characteristics. AIMS Microbiology, 2025, 11(1): 1-21. doi: 10.3934/microbiol.2025001
    [10] Ogueri Nwaiwu, Chiugo Claret Aduba . An in silico analysis of acquired antimicrobial resistance genes in Aeromonas plasmids. AIMS Microbiology, 2020, 6(1): 75-91. doi: 10.3934/microbiol.2020005
  • In this paper, we introduced a new subclass SSC(α,δ,A,B) of tilted star-like functions with respect to symmetric conjugate points in an open unit disk and obtained some of its basic properties. The estimation of the Taylor-Maclaurin coefficients, the Hankel determinant, Fekete-Szegö inequality, and distortion and growth bounds for functions in this new subclass were investigated. A number of new or known results were presented to follow upon specializing in the parameters involved in our main results.



    In 2017, Khalid and Shahbaz [1] introduced the notions of totient, super totient and hyper totient numbers (see also [2]). Recall in this regard that a positive integer t is said to be totient if the sum of its co-prime residues is 2kt, with k1. Further, a positive integer s is called super totient if its set of co-prime residues can be divided into two nonempty disjoint subsets with equal sum. Finally, a positive integer h is said to be hyper totient if its set of co-prime residues including h can be divided into two nonempty disjoint subsets with equal sum. This paper focuses on the use of hyper totient numbers in graph labeling.

    The assignment of positive integers as labels of vertices and/or edges of a graph is a classic problem in graph theory (see, for instance, [3,4,5]), with a broad range of applications in real daily life problems as networking, coding theory, digital design, database or management, amongst other areas. Nowadays, the problem of finding and characterizing new classes of integers satisfying certain given conditions, together with the problem of finding illustrative families of graphs for which a labeling based on such classes exists, constitutes a challenge for researchers in both number and graph theory. In the recent literature, one can find a wide amount of examples in this regard [6,7,8,9]. Of particular interest for the topic of this paper, it is remarkable the recent studies of Shahbaz and Khalid [1,10] on graph labelings based on super totient numbers, and the introduction of both concepts of restricted super totient labeling and super totient index of graphs by Joshua and Wong [11].

    The paper is organized as follows. In Section 2, we describe some preliminary concepts and results on graph theory and hyper totient numbers that are used throughout the paper. Then, we introduce in Section 3 the concept of (restricted) hyper totient graph labeling. In particular, we prove that every finite graph is hyper totient. Finally, we investigate in Section 4 under which assumptions the following families of graphs constitute restricted hyper totient graphs: complete graphs, star graphs, complete bipartite graphs, wheel graphs, cycles, paths, fan graphs and friendship graphs.

    This section deals with some preliminary concepts, notations and results on graph theory and hyper totient numbers that are used throughout the paper. For more details about these topics, we refer the reader to the manuscripts [1,10,12].

    A graph is any pair G=(V,E) formed by a set V of vertices and a set E of edges so that each edge joins two vertices, which are then said to be adjacent. The number of vertices and the number of edges of G constitute, respectively, the order and size of G. A graph is said to be finite if both its order and size are finite. A subetaaph of G is any graph H=(W,F) such that WV and FE. The set of vertices that are adjacent to a given vertex vV constitutes its neighborhood NG(v). The number of such vertices constitutes the degree dG(v) of such a vertex v. The minimum vertex degree of the graph G is denoted δ(G).

    From now on, let vw be the edge formed by two vertices v,wV. If v=w, then it is a loop. A graph is called simple if it does not contain loops. Two graphs G1=(V1,E1) and G2=(V2,E2) are said to be isomorphic if there exists a bijection f:V1V2 such that uvE1 if and only if f(u)f(v)E2.

    A finite graph is called complete if all its vertices are pairwise adjacent. The complete graph of order n is denoted Kn. Further, the complete bipartite graph Km,n is the finite graph of order m+n whose set of vertices may be partitioned into two subsets of respective sizes m and n so that every edge of the graph contains a vertex of each one of these two sets. The complete bipartite graph K1,n, with n>2, is called a star graph. Its center is the unique vertex that is contained in all the edges.

    A path between two distinct vertices v and w of a given finite graph G is any ordered sequence of adjacent and pairwise distinct vertices v0=v,v1,,vn2,vn1=w in G, with n>2. If v=w, then it constitutes a cycle. As such, paths and cycles are also finite graphs. From here on, let Pn and Cn respectively denote the path and the cycle of order n. A graph is connected if there always exists a path between any pair of vertices. If no subetaaph of a connected graph G is a cycle, then G is called a tree.

    Further, the wheel graph Wn results after joining all the vertices of the cycle Cn to a new vertex, which is called the center of the wheel graph. The fan graph Fm,n is the graph that results after joining each vertex of a set of m isolated vertices with all the vertices of the path Pn. Finally, the friendship graph Fn is the graph that results after joining n copies of the cycle C3 with a common vertex. Figure 1 illustrates the different families of graphs that we have enumerated until now.

    Figure 1.  Illustrative examples of a path, a cycle, a complete graph, a complete bipartite graph, a star graph, a wheel graph, a fan graph and a friendship graph.

    A vertex-labeling of a graph G is any map f:VN assigning |V| positive integers or labels to the set of vertices V. It gives rise to the induced multiplicative edge-labeling f:EN so that f(vw)=f(v)f(w), for all vwE. In 2017, Khalid and Shahbaz [1] defined a super totient graph as any finite graph G for which there exists an injective vertex-labeling f (which is called super totient labeling of G) whose induced multiplicative edge-labeling f assigns a super totient number to each one of its edges. In particular, they proved that every finite graph is super totient. Much more recently, Joshua and Wong [11] defined the super totient index of a finite graph G as the minimum cardinality of the image of f, for every super totient labeling f of G. In this paper, we focus on those injective vertex-labelings f so that the image of the induced map f is only formed by hyper totient numbers. To this end, the following result characterizing this type of numbers is of particular interest. It gathers together the different results on this subject that are enumerated in [2].

    Theorem 2.1. Every hyper totient number is a positive integer n>2 satisfying exactly one of the following two assertions.

    a) It is an even integer distinct from 10 and 30.

    b) It is a prime power pk, with k1, where p is a prime such that p3(mod4).

    Proof. If n<32, then the result follows readily from a simple computational check (see, for instance, [2,Table 1]). Further, according to [2,Theorem 3.6], a positive integer n32 is hyper totient if and only if n(φ(n)+2) is divisible by 4. Here, φ(n) denote the Euler's totient number associated to n. That is, the number of co-prime residues of n. The result holds from the following study of cases.

    ● If n is even, then n(φ(n)+2) is divisible by 4, because φ(m) is also even, whatever the positive integer m is. Hence, n is hyper totient.

    ● If n is odd, then n is hyper totient if and only if φ(n)+2 is divisible by 4. Equivalently, if n=mi=1pkii is the prime factorization of n, then φ(n)=mi=1pki1i(pi1)2(mod4). Since n is an odd integer, we have that pi is also odd, for all im. Thus, φ(n)2(mod4) if and only if m=1 in the previous prime factorization. (Otherwise, if m>1, then φ(n) would be divisible by 4.) Hence, n=pk, for some prime p3(mod4). (Notice to this last end that it would be φ(n)=pk1(p1)2(mod4), where p is odd.)

    In this section, we show how hyper totient numbers may be implemented in graph labeling. In this regard, we say that a finite graph G=(V,E) is an hyper totient graph if there exists an injective vertex-labeling f of G whose induced multiplicative edge-labeling f assigns a hyper totient number to each edge in E. In such a case, we say that the map f is an hyper totient labeling (HTL) and that the graph G is an hyper totient graph (HTG). In order to illustrate these concepts, Figure 2 shows an HTG of order five and size ten, whose vertices are uniquely labeled by the positive integers of the subset {2,3,4,6,7}N and whose set of edges is then labeled by the set of totient numbers {4,6,8,9,12,14,16,36,49}. In order to distinguish both vertex- and edge-labelings, they are respectively colored in blue and black. Notice the fact that this graph is not simple.

    Figure 2.  Example of hyper totient labeling of a hyper totient graph.

    Similarly to the concept of super totient index, which was introduced by Joshua and Wong in [11], we define the hyper totient index of the graph G as

    h(G):=min{|f(V)|:f is an HTL of G}.

    Then, we say that an HTL f of the graph G is optimal if |f(V)|=h(G). In an analogous way to the result obtained by the mentioned authors in [11,Lemma 4.3], the following lemma holds.

    Lemma 3.1. Let G be an HTG. There always exists an optimal HTL of G whose image is contained in the set {3i:iN}.

    Proof. Let f be an optimal HTL of the graph G and let V={v1,,vn} be its set of vertices. Then, let {p1,,pt} be a set of primes such that f(vi)=tj=1paijj, for all positive integers in, where each aij is a non-negative integer. Let m=1+max{aij:1in,1jt}. Then, Theorem 2.1 implies that the map g:V{3i:iN} that is described so that g(vi)=3tk=1aikmk1 constitutes an optimal HTL of the graph G.

    The previous result enables us to ensure the equivalence of super totient and hyper totient indices, and the subsequent result concerning the fact that every finite graph is an HTG.

    Theorem 3.2. Both the hyper totient index and the super totient index of any given finite graph coincide.

    Proof. Let f be an injective vertex-labeling of a graph G=(V,E). This map induces the additive edge-labeling f+:EN so that f+(vw)=f(v)+f(w), for all vwE. In addition, it is defined the sum index of the graph G as

    min{|f+(V)|:f is an injective vertex-labeling of G}.

    As a simple consequence of Lemma 3.1, the hyper totient index of the graph G coincides with the sum index of such a graph. The result follows simply from the fact that, according to [11,Theorem 4.5], this last index also coincides with the super totient index of the graph G.

    Corollary 3.3. Every finite graph constitutes an HTG.

    Proof. The result follows straighforwardly from Theorem 3.2 and the fact that every finite graph is a super totient graph (see [1,Theorem 5.5]).

    We say that a finite graph G=(V,E) is a restricted hyper totient graph (RHTG) if it is a simple HTG whose set of vertices may be labeled by the subset of positive integers {1,,|V|}. The corresponding vertex-labeling is termed a restricted hyper totient labeling (RHTL) of G. Thus, for instance, Figure 3 illustrates a RHTL of order and size six, whose set of edges is labeled by the set of totient numbers {3,4,6,12}. Again, the vertex-labeling is colored in blue and the edge-labeling is colored in black.

    Figure 3.  Example of a restricted hyper totient graph.

    Of particular interest for the development of our work is the RHTG having maximum size for each given order. It is described as follows. Let n be the RHTG of order n that is defined so that there is an edge between the vertices labeled as i and j, with 1ijn, if and only if the product ij is a hyper totient number. Figure 4 illustrates this graph n, for all positive integers n9. In order to avoid a tangled mess of labels, we remove from now on the edge-labeling of the corresponding graphs.

    Figure 4.  The RHTG n, for all n9.

    The following result follows straightforwardly from the previous definitions.

    Lemma 4.1. For n>3, every spanning subetaaph of n is an RHTG.

    Lemma 4.1 enables us to ensure that the finding of RHTGs is completely solved once one may construct the graph n, for every positive integer n. In this regard, and based on Theorem 2.1, Algorithm 1 describes a simple computational method of time complexity O(n2) for determining this graph n.

    Algorithm 1 Construction of the graph n.
    1. procedure R(n)
    2:   V(n)={1,,n};
    3:   fori1,n do
    4:     forji+1,n do
    5:       if ij satisfies either Condition (a) or Condition (b) in Theorem 2.1 then
    6:           E(n)E(n){ij};
    7:       end if
    8:     end for
    9:   end for
    10:   return n=(V(n),E(n))
    11: end procedure

     | Show Table
    DownLoad: CSV

    In this section, we study under which assumptions the following types of graphs constitute RHTGs: a complete graph Kn, a star graph K1,n, a complete bipartite graph Km,n, a wheel graph Wn, a cycle Cn, a path Pn, a fan graph F1,n and a friendship graph Fn. Notice that, according to Lemma 4.1, any subetaaph of any of these types of graphs satisfying the mentioned assumptions constitutes also an RHTG. Firstly, we focus on the complete graph Kn.

    Proposition 4.2. Let n be a positive integer. Then, the complete graph Kn is an RHTG if and only if n=1.

    Proof. The case n=1 is trivial. Further, the case n2 follows straightforwardly from the fact that the vertices labeled as 1 and 2 must be adjacent, but the induced edge label 2 is not a hyper totient number.

    Proposition 4.3. Let n>2 be a positive integer. Then, the star graph K1,n is a spanning subetaaph of n+1. As a consequence, every star graph constitutes an RHTG.

    Proof. According to Theorem 2.1, every multiple of 4 is a hyper totient number. Hence, the spanning subetaaph of n+1 having as edges those ones containing the vertex labeled as 4 constitutes a star graph K1,n. This vertex corresponds indeed to the center of the star graph. The consequence follows readily from Lemma 4.1.

    Theorem 4.4. Let m and n be two positive integers such that 2mn. The complete bipartite graph Km,n is an RHTG if and only one of the following assertions hold.

    a) m=n=2.

    b) m=2 and n6.

    c) 3m11 and nm+6.

    d) m12 and nm+8.

    Proof. Figure 5 illustrates the case m=n=2. Thus, let us suppose the existence of two positive integers m2 and n2 such that m+n>4 and Km,n is an RHTG. Let vi denote the vertex that is labeled as i{1,,m+n} in the graph m+n. Since 10 is not a hyper totient number, the two vertices v2 and v5 must belong to the same part of Km,n. Let P denote such a part. Then,

    NKm,n(v2)=NKm,n(v5)=Km,nPNm+n(v2)Nm+n(v5).
    Figure 5.  RHTL of the complete bipartite graph K2,2.

    From Theorem 2.1, we have that

    Nm+n(v5)={v4}{v2k:4km+n2}Nm+n(v2).

    In particular, since 2mn, it must be m+n8 and n=|P|. Moreover, Theorem 2.1 enables us to ensure that every vertex in the set Nm+n(v5), except for v10 (if m+n10) and v30 (if m+n30), is adjacent to any other vertex in the set m+n. Notice to this end that all the indices of such vertices are even integers and that both vertices v10 and v30 are not adjacent to v1P. Due to this last aspect, it must be {v10,v30}P. As a consequence,

    m+n{8, if m=2,2(m+3), if 3m11,2(m+4), if m12.

    Let αm,n denote the previous lower bound, for the positive integers m and n under consideration. Then, in order to get an RHTL of the graph Km,n, it is enough to take

    Km,nP={v2k:2kαm+n2}{v6,v10,v30}.

    Figure 6 illustrates an RHTL for the complete bipartite graph K4,13.

    Figure 6.  RHTL of the complete bipartite graph K4,13.

    Theorem 4.5. Every tree containing at least 32 vertices is an RHTG.

    Proof. The result follows straightforwardly from Lemma 4.1, Proposition 4.3 and Theorem 4.4 once it is noticed that every tree is a bipartite graph.

    Theorem 4.6. The wheel graph Wn is an RHTG if and only if n9.

    Proof. Throughout this proof, let vi denote the vertex labeled as iN in the graph under consideration. Notice in Figure 4 that δ(n)2, for all positive integer n9. To this end, observe in the mentioned figure the vertex v1, if 1n5, and the vertex v5, if 6n9. Then, since δ(Wn)=3, for all positive integers n, we have from Lemma 4.1 that the wheel graph Wn is not an RHTG, if n<9.

    Now, Figure 7 illustrates an RHTL of the wheel graph W9. If we replace the edge v10v6 in that figure by the path v10,v11,,vn+1,v6, so that all the vertices are joined with the center v4 by an edge, then Theorem 2.1 implies that the resulting vertex-labeling is an RHTL of the wheel graph Wn.

    Figure 7.  RHTL of the wheel graph W9.

    Theorem 4.7. Let n>2 be a positive integer. Then, the cycle graph Cn is an RHTG if and only if n=4 or n8.

    Proof. Again, let vi denote the vertex labeled as iN in the graph under consideration. Notice in Figure 4 that δ(n)1, for all positive integer n7, except for n=4. To this end, observe in the mentioned figure the vertex v1, if 1n3, and the vertex v5, if 5n7. Then, since δ(Cn)=2, for all positive integers n, we have from Lemma 4.1 that the cycle Cn is not an RHTG, if n{3,5,6,7}.

    Now, Figures 5 and 8 illustrate, respectively, RHTLs of the cycles C4, which is isomorphic to the complete bipartite graph K2,2, and C8. Finally, if n9, then the result follows simply from Lemma 4.1 and Theorem 4.6, once it is noticed that the cycle Cn is a subetaaph of the wheel graph Wn+1.

    Figure 8.  RHTL of the cycle C8.

    Theorem 4.8. Every path is an RHTG.

    Proof. Firstly, notice that the path P3 is isomorphic to the graph 3, and hence, it constitutes an RHTG. In addition, if n=4 or n8, then the result follows simply from Lemma 4.1 and Theorem 4.7, once it is noticed that the path Pn is a subetaaph of the cycle Cn. Finally, the case n{5,6,7} is illustrated by the RHTL of the path P7 in Figure 9, which contains implicitly the RHTLs of both paths P5 and P6 as subetaaphs.

    Figure 9.  RHTL of the path P7.

    Theorem 4.9. Let n>2 be a positive integer. Then, the fan graph F1,n is an RHTG if and only if n9.

    Proof. Since δ(F1,n)=2, for all positive integers n>2, Lemma 4.1 enables us to ensure that the fan graph F1,n is not an RHTG, for all n{4,5,6}, because δ(n+1)=1 in such cases. Further, the case n9 follows simply from Lemma 4.1 and Theorem 4.6, once it is noticed that the fan graph F1,n is a subetaaph of the wheel graph Wn. Finally, the case n{3,7,8} is illustrated by the RHTLs of the fan graphs F1,3 and F1,8 in Figure 10. Notice to this end that the RHTL of the fan graph F1,7 is implicitly indicated in that one of the fan graph F1,8, of which the former constitutes a subetaaph.

    Figure 10.  RHTLs of the fan graphs F1,3 and F1,8.

    Theorem 4.10. The friendship graph Fn is an RHTG if and only if n4.

    Proof. Since the order of the friendship graph Fn is 2n+1 and δ(n)=1, for all n{3,5,7}, then Lemma 4.1 implies that the friendship graph Fn is not an RHTG, for all n3. Further, the case n4 follows simply from Lemma 4.1 and Theorem 4.6, once it is noticed that the friendship graph Fn is a subetaaph of the wheel graph Wm, for all m2n.

    In this paper, we have introduced the notion of hyper totient graph as any finite graph G=(V,E) admitting an injective vertex-labeling f:VN so that its induced multiplicative edge-labeling assigns a hyper totient number to each edge. We have proved in particular that every finite graph is hyper totient. Furthermore, we have introduced the concept of restricted hyper totient graph as a hyper totient graph of order n whose vertices are labeled by the elements of the set {1,,n}. Then, we have determined under which assumptions some well-known families of graphs are restricted hyper totient.

    Of course, the current manuscript constitutes a starting point for the study of hyper totient graphs, but a much deeper study is required in order to characterize all the structural properties of this type of graphs. In this regard, we propose as further work the study of locating, dominating and independent sets within a given RHTG, together with their corresponding locating, dominating and independent numbers. We also propose the following open questions for further work on this subject.

    Problem 5.1. In Theorem 4.5, we have determined a lower bound for the number of vertices of a tree in order to ensure that the latter is an RHTG. But, what about trees of smaller orders? A similar reasoning to that one developed by Joshua and Wong in [11,Theorem 3.9] may be done in this regard.

    Problem 5.2. In 2001, Beineke and Hedge [13] defined a strongly multiplicative graph as a finite graph of order n for which there exists an injective vertex-labeling f:V{1,,n} so that the induced multiplicative edge-coloring f is injective. In a similar way, we may introduce here the notion of strongly hyper totient graph (SHTG) as an RHTG having distinct all the hyper totient numbers that are used for labeling its edges. Notice in this regard that the majority of RHTGs appearing in the figures of this paper are not SHTGs. The study of this type of RHTGs is established as further work.

    Problem 5.3. Under which assumptions is the condition of being RHTG preserved by the different graph products existing in the literature? A similar question may be dealt with concerning the just introduced notion of SHTG.

    Falcón's work is partially supported by the research project FQM-016 from Junta de Andalucía. In addition, the authors want to express their gratitude to the anonymous referees for the comprehensive reading of the paper and their pertinent comments and suggestions, which helped improve the manuscript.

    All authors are here with confirm that there are no competing interests between them.



    [1] W. Janowski, Some extremal problems for certain families of analytic functions, Ann. Pol. Math., 28 (1973), 297–326. https://doi.org/10.4064/ap-28-3-297-326 doi: 10.4064/ap-28-3-297-326
    [2] R. M. El-Ashwah, D. K. Thomas, Some subclasses of close-to-convex functions, J. Ramanujan Math. Soc., 2 (1987), 85–100.
    [3] S. A. Halim, Functions starlike with respect to other points, Int. J. Math. Math. Sci., 14 (1991), 620597. https://doi.org/10.1155/s0161171291000613 doi: 10.1155/s0161171291000613
    [4] L. C. Ping, A. Janteng, Subclass of starlike functions with respect to symmetric conjugate points, International Journal of Algebra, 5 (2011), 755–762.
    [5] K. Sakaguchi, On a certain univalent mapping, J. Math. Soc. Japan, 11 (1959), 72–75. https://doi.org/10.2969/jmsj/01110072 doi: 10.2969/jmsj/01110072
    [6] T. N. Shanmugam, C. Ramachandram, V. Ravichandran, Fekete-Szegö problem for subclasses of starlike functions with respect to symmetric points, Bull. Korean Math. Soc., 43 (2006), 589–598. http://dx.doi.org/10.4134/BKMS.2006.43.3.589 doi: 10.4134/BKMS.2006.43.3.589
    [7] S. A. F. M. Dahhar, A. Janteng, A subclass of starlike functions with respect to conjugate points, Int. Math. Forum., 4 (2009), 1373–1377.
    [8] Q. H. Xu, G. P. Wu, Coefficient estimate for a subclass of univalent functions with respect to symmetric point, European Journal of Pure and Applied Mathematics, 3 (2010), 1055–1061.
    [9] G. Singh, G. Singh, Coefficient inequality for subclasses of starlike functions with respect to conjugate points, International Journal of Modern Mathematical Sciences, 8 (2013), 48–56.
    [10] G. Singh, Hankel determinant for analytic functions with respect to other points, Eng. Math. Lett., 2 (2013), 115–123.
    [11] A. Yahya, S. C. Soh, D. Mohamad, Coefficient bound of a generalised close-to-convex function, International Journal of Pure and Applied Mathematics, 83 (2013), 287–293.
    [12] A. Yahya, S. C. Soh, D. Mohamad, Some extremal properties of a generalised close-to-convex function, Int. J. Math. Anal., 8 (2014), 1931–1936. http://doi.org/10.12988/ijma.2014.44109 doi: 10.12988/ijma.2014.44109
    [13] N. H. A. A. Wahid, D. Mohamad, S. C. Soh, On a subclass of tilted starlike functions with respect to conjugate points, Discovering Mathematics, 37 (2015), 1–6.
    [14] D. Vamshee Krishna, B. Venkateswarlu, T. RamReddy, Third Hankel determinant for starlike and convex functions with respect to symmetric points, Ann. Univ. Mariae Curie-Skłodowska Sect. A, 70 (2016), 37–45. http://doi.org/10.17951/a.2016.70.1.37 doi: 10.17951/a.2016.70.1.37
    [15] A. K. Mishra, J. Prajapat, S. Maharana, Bounds on Hankel determinant for starlike and convex functions with respect to symmetric points, Cogent Mathematics, 3 (2016), 1160557. http://doi.org/10.1080/23311835.2016.1160557 doi: 10.1080/23311835.2016.1160557
    [16] N. H. A. A. Wahid, D. Mohamad, Bounds on Hankel determinant for starlike functions with respect to conjugate points, J. Math. Comput. Sci., 11 (2021), 3347–3360. https://doi.org/10.28919/jmcs/5722 doi: 10.28919/jmcs/5722
    [17] N. H. A. A. Wahid, D. Mohamad, Toeplitz determinant for a subclass of tilted starlike functions with respect to conjugate points, Sains Malays., 50 (2021), 3745–3751. http://doi.org/10.17576/jsm-2021-5012-23 doi: 10.17576/jsm-2021-5012-23
    [18] P. Zaprawa, Initial logarithmic coefficients for functions starlike with respect to symmetric points, Bol. Soc. Mat. Mex., 27 (2021), 62. https://doi.org/10.1007/s40590-021-00370-y doi: 10.1007/s40590-021-00370-y
    [19] H. Tang, K. R. Karthikeyan, G. Murugusundaramoorthy, Certain subclass of analytic functions with respect to symmetric points associated with conic region, AIMS Mathematics, 6 (2021), 12863–12877. http://doi.org/10.3934/math.2021742 doi: 10.3934/math.2021742
    [20] K. Trạbka-Wiẹcław, On coefficient problems for functions connected with the sine function, Symmetry, 13 (2021), 1179. http://doi.org/10.3390/sym13071179 doi: 10.3390/sym13071179
    [21] D. Mohamad, N. H. A. A. Wahid, Zalcman coefficient functional for tilted starlike functions with respect to conjugate points, J. Math. Comput. Sci., 29 (2023), 40–51. http://doi.org/10.22436/jmcs.029.01.04 doi: 10.22436/jmcs.029.01.04
    [22] R. M. Goel, B. C. Mehrok, A subclass of univalent functions, J. Aust. Math. Soc., 35 (1983), 1–17. http://doi.org/10.1017/S1446788700024733 doi: 10.1017/S1446788700024733
    [23] I. Efraimidis, A generalization of Livingston's coefficient inequalities for functions with positive real part, J. Math. Anal. Appl., 435 (2016), 369–379. http://doi.org/10.1016/j.jmaa.2015.10.050 doi: 10.1016/j.jmaa.2015.10.050
    [24] P. L. Duren, Univalent functions, New York: Springer, 1983.
  • This article has been cited by:

    1. Wen Ching Ooi, Debbie Dominic, Mohd Asyraf Kassim, Siti Baidurah, Biomass Fuel Production through Cultivation of Microalgae Coccomyxa dispar and Scenedesmus parvus in Palm Oil Mill Effluent and Simultaneous Phycoremediation, 2023, 13, 2077-0472, 336, 10.3390/agriculture13020336
    2. Olalekan S. Alade, Modeling and simulation of an integrated bioethanol-hydrogen production process, 2024, 15, 1759-7269, 943, 10.1080/17597269.2024.2306010
    3. Debbie Dominic, Siti Baidurah, Biomass Fuel Production through Fermentation of Lysinibacillus sp. LC 556247 in Various Ratios of Palm Oil Mill Effluent and Empty Fruit Bunch, 2023, 11, 2227-9717, 1444, 10.3390/pr11051444
    4. Ras Izzati Ismail, Chu Yee Khor, Alina Rahayu Mohamed, Pelletization Temperature and Pressure Effects on the Mechanical Properties of Khaya senegalensis Biomass Energy Pellets, 2023, 15, 2071-1050, 7501, 10.3390/su15097501
    5. Manpreet Kaur, Ashish Kumar Singh, Ajay Singh, Bioconversion of food industry waste to value added products: Current technological trends and prospects, 2023, 55, 22124292, 102935, 10.1016/j.fbio.2023.102935
    6. Tonni Agustiono Kurniawan, Mehwish Ali, Ayesha Mohyuddin, Ahtisham Haider, Mohd Hafiz Dzarfan Othman, Abdulkader Anouzla, Hui Hwang Goh, Dongdong Zhang, Wei Dai, Faissal Aziz, Muhammad Imran Khan, Imran Ali, Mohamed Mahmoud, Sadeq Abdullah Abdo Alkhadher, G. Abdulkareem Alsultan, Innovative Transformation of Palm Oil Biomass Waste into Sustainable Biofuel: Technological Breakthroughs and Future Prospects, 2024, 09575820, 10.1016/j.psep.2024.11.073
    7. Siti Suraya Munirah Normi, Siti Baidurah, 2024, Chapter 12, 978-981-97-8556-8, 261, 10.1007/978-981-97-8557-5_12
    8. Debbie Dominic, Siti Baidurah, A review of biological processing technologies for palm oil mill waste treatment and simultaneous bioenergy production at laboratory scale, pilot scale and industrial scale applications with technoeconomic analysis, 2025, 25901745, 100914, 10.1016/j.ecmx.2025.100914
    9. Kai Chen Goh, Tonni Agustiono Kurniawan, G. Abdulkareem AlSultan, Mohd Hafiz Dzarfan Othman, Abdelkader Anouzla, Faissal Aziz, Imran Ali, Joan Cecilia C. Casila, Muhammad Imran Khan, Dongdong Zhang, Choo Wou Onn, Ta Wee Seow, Haryati Shafii, Innovative circular bioeconomy and decarbonization approaches in palm oil waste management: A review, 2025, 195, 09575820, 106746, 10.1016/j.psep.2024.12.127
  • Reader Comments
  • © 2023 the Author(s), licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0)
通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索

Metrics

Article views(1518) PDF downloads(72) Cited by(2)

Figures and Tables

Tables(4)

/

DownLoad:  Full-Size Img  PowerPoint
Return
Return

Catalog