arXiv subjects
Publications and source records attributed to Hitoshi Shiraishi.
Let H[a_0,n] be the class of functions p(z)=a_0+a_nz^n+... which are analytic in the open unit disk U. For p(z)in H[1,2], M. Nunokawa, S. Owa, N. Uyanik and H. Shiraishi (Math. Comput. Modelling. 55 (2012), 1245-1250) have shown some theorems for argument properties. The object of the present paper is to discuss some extensions of Nnnokawa lemma and its applications for argument properties.
For analytic functions f(z) in the open unit disk U with f(0)=f'(0)-1=0, S. S. Miller and P. T. Mocanu (Integral Transform. Spec. Funct. 19(2008)) have considered some sufficient problems for starlikeness. The object of the present paper is to discuss some sufficient problems for f(z) to be in some classes of order α.
For analytic functions f(z) in the open unit disk U with f(0)=f'(0)-1=0, R. Singh and S. Singh (Coll. Math. 47(1982), 309-314) have considered some sufficient problems for f(z) to be univalent in U. The object of the present paper is to discuss some sufficient problems for f(z) to be some classes of analytic functions in U.
There are many results for sufficient conditions of functions f(z) which are analytic in the open unit disc U to be starlike and convex in U. The object of the present paper is to derive some interesting sufficient conditions for f(z) to be starlike of order α and convex of order α in U concerned with Jack's lemma. Some examples for our results are also considered with the help of Mathematica 5.2.
For analytic functions f(z) in the open unit disk U with f(0)=f'(0)-1=0, P. T. Mocanu (Mathematica (Cluj), 11(34) (1969)) have considered Mocanu functions. The object of the present paper is to discuss some sufficient problems for f(z) to be starlike of order α.
For analytic functions f(z) in the open unit disk U with f(0)=f'(0)-1=0, a class STC(μ) is defined. The object of the present paper is to discuss some sufficient problems for f(z) to be strongly close-to-convex of order μ in U.
For analytic functions f(z) in the closed unit disk \bar{U}, two boundary points z_1 and z_2 such that α= (f'(z_1)+f'(z_2))/2 in f'(U) are considered. The object of the present paper is to discuss some interesting conditions for f(z) to be |f'(z)-1|<ρ|1-α| in U with some examples.
Let H[a_0,n] be the class of functions f(z)=a_0+a_nz^n+...which are analytic in the open unit disk U}. For f(z) in H[a_0,n], S. S. Miller and P. T. Mocanu (J. Math. Anal. Appl. 65(1978), 289-305) have shown Miller and Mocanu lemma which is the generalization of Jack lemma by I. S. Jack (J. London Math. Soc. 3(1971), 469-474). Applying Miller and Mocanu lemma, an interesting property for f(z) in H[a_0,n] and an example are discuss.
Let A_n be the class of functions f(z) which are analytic in the open unit disk U} with f(0)=0, f'(0)=1, f"(0)=f"'(0)=...=f^{(n)}=0 and f^{(n+1)}\neq0. Applying the results due to S. S. Miller (J. Math. Anal. Appl. 65(1978), 289-305), some interesting starlikeness problems concerned with subordinations are discussed. The results in the paper are extensions of results by M. Obradović (Hokkaido Math. J. 27(1998), 329-335).
Applying the subordination principle for analytic functions in the open unit disk U, I. H. Kim and N. E. Cho (Comput. Math. Appl. 59(2010), 2067-2073) considered some sufficient conditions for Carathéodory functions. The purpose of this paper is to discuss some sufficient conditions for the class of strongly Carathéodory functions in U.
For analytic functions f(z) in the open unit disk U with f(0)=f'(0)-1=f"(0)=0, P. T. Mocanu (Mathematica (Cluj), 42(2000)) has considered some sufficient arguments of f'(z)+zf"(z) for |\arg(zf'(z)/f(z))|<πμ/2. The object of the present paper is to discuss those probrems for f(z) with f"(0)=f"'(0)=...=f^{(n)}(0)=0 and f^{(n+1)}(0) \ne 0.
For the analytic function f(z), H. Shiraishi and S. Owa (Stud. Univ. Babes-Bolyai Math. 55(2010), 207-211) have shown a theorem for the minimum value of |f(z)|. In this paper, we discuss an application of this theorem and some corollaries.
For analytic functions p(z) in the open unit disk U with p(0)=1, Nunokwa has given a result which called Nunokawa lemma (Proc. Japan Acad., Ser. A 68 (1992)). By studying Nunokawa lemma, we obtain this expansion. In this paper, we introduce this result and its example.
Let $\mathcal{B}$ be the class of functions $w(z)$ of the form $w(z)=\sum\limits_{k=1}^{\infty}b_k z^k$ which are analytic and satisfy the condition $|w(z)|<1$ in the open unit disk $\mathbb{U}=\left\{z\in \mathbb{C}:|z|<1\right\}$. Then we call $w(z)\in \mathcal{B}$ the Schwarz function. In this paper, we discuss new coefficient estimates for Schwarz functions by applying the lemma due to Livingston (Proc. Amer. Math. Soc. 21(1969), 545--552).