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In this paper, motivated by the work of Kim and Kolar for the case of pseudoconvex models which are sums of squares of polynomials, we study the Lie algebra of real-analytic infinitesimal $CR$ automorphisms of a model hypersurface $M_0$ given by \begin{equation} M_0= \{(z,w) \in \mathbb C^{3} \times \mathbb C \ | \ \Im w= P\bar Q + Q\bar P + R\bar R \}, \end{equation} where $P,$ $Q$ and $R$ are homogeneous polynomials. In particular, we classify $M_0$ with respect to the description of its nilpotent rotations when $P,$ $Q$ and $R$ are monomials. We also give an example of a model $M_0$ for which the real dimension of its generalized (exotic) rotations is $3.$

Let $f$ be a univalent self-map of the unit disc. We introduce a technique, that we call {\sl semigroup-fication}, which allows to construct a continuous semigroup $(\phi_t)$ of holomorphic self-maps of the unit disc whose time one map $\phi_1$ is, in a sense, very close to $f$. The semigrup-fication of $f$ is of the same type as $f$ (elliptic, hyperbolic, parabolic of positive step or parabolic of zero step) and there is a one-to-one correspondence between the set of boundary regular fixed points of $f$ with a given multiplier and the corresponding set for $\phi_1$. Moreover, in case $f$ (and hence $\phi_1$) has no interior fixed points, the slope of the orbits converging to the Denjoy-Wolff point is the same. The construction is based on holomorphic models, localization techniques and Gromov hyperbolicity. As an application of this construction, we prove that in the non-elliptic case, the orbits of $f$ converge non-tangentially to the Denjoy-Wolff point if and only if the Koenigs domain of $f$ is "almost symmetric" with respect to vertical lines.

For any given sum of squares domain in $\mathbb{C}^n,$ we reduce the complexity in Catlin's multitype techniques by giving a complete normalization of the geometry. Using this normalization result, we present a more elementary proof of the equality of the Catlin multitype and the commutator multitype for such domains when both invariants are finite. Finally, we reformulate algebraically Catlin's machinery for the commutator multitype computation at the origin for any given sum of squares domain in $\mathbb{C}^n$.

The following is a Ph.D. thesis. The thesis is submitted in partial fulfillment of the requirements for the degree of Philosophiae Doctor (Ph.D.) at the Norwegian University of Science and Technology.

We prove that every 1-Lipschitz map from a closed metric surface onto a closed Riemannian surface that has the same area is an isometry. If we replace the target space with a non-smooth surface, then the statement is not true and we study the regularity properties of such a map under different geometric assumptions. Our proof relies on a coarea inequality for continuous Sobolev functions on metric surfaces that we establish, and which generalizes a recent result of Esmayli--Ikonen--Rajala., 28 pages

The main result of this paper is that an entire function $f$ that is in $L^2(\mathbb C^n,\psi)$ with respect to the weight $\psi(z)=2mH_S(z)+\gamma\log(1+|z|^2)$ is a polynomial with exponents in $m\widehat S_\Gamma$. Here $H_S$ is the logarithmic supporting function of a compact convex set $S\subset \mathbb R^n_+$ with $0\in S$, $\gamma\geq 0$ is small enough in terms of $m$, and $\widehat S_\Gamma$ is the hull of $S$ with respect to a certain cone $\Gamma$ depending on $S$, $m$ and $\gamma$. An example showing that in general $\widehat S_\Gamma$ can not be replaced by $S$ is constructed., Comment: 7 pages, 2 figures

Let $H$ and $F$ be two Hénon maps with biholomorphically equivalent escaping sets, then there exist affine automorphisms $A_1$ and $A_2$ in $\mathbb{C}^2$ such that \[ F=A_1\circ H \circ A_2 \] in $\mathbb{C}^2$., Major revision, to appear in Mathematische Annalen

We prove that if a fractal set in $\mathbb{R}^d$ avoids lines in a certain quantitative sense, which we call line porosity, then it has a fractal uncertainty principle. The main ingredient is a new higher dimensional Beurling-Malliavin multiplier theorem., Comments welcome!

In this paper, we give a new characterization of the split-complex numbers as a vector space $LC_2= \{xI+yE : x,y \in \mathbb{R},\, E^2=I \}$ of operators, where $I$ is the identity operator and $E$ is the unit shift operator that are operating on the space $\mathbb{P}_2$ of all real-valued $2$-periodic functions. We also characterize the field of the complex number $\mathbb{C}= \{x+yi: x, y \in \mathbb{R}, i^2 =-1 \}$ as the space of linear operators of the form $ \{xI+yE, E^2 = -I \}$, where $I$ is the identity operator and $E$ the unit shift operator that are regarded as operating on the vector space $\mathbb{AP}_2 $ of all real-valued $2$-antiperiodic functions. In an analogy to the polar form of complex numbers, we form the hyperbolic form of some subset $ \mathcal{H} $ of the elements of $LC_2 $. We study some properties of the elements of $LC_2$, the trace, the determinant, invertibility conditions, and others. We study some elementary functions defined on subsets of $LC_2$ as compared and contrasted with the usual complex functions. We study properties like continuity, differentiability and define the holomorphic condition of $LC_2$ functions in a different sense than complex functions. We establish the line integrals of the vector-valued functions in $LC_2$ and compare them against the well known results for complex functions of a complex variable., 26 pages, 2 figures, one table

A generalization of the second main theorem of tropical Nevanlinna theory is presented for noncontinuous piecewise linear functions and for tropical hypersurfaces without requiring a growth condition. The method of proof is novel and significantly more straightforward than previously known proofs. The tropical analogue of the Nevanlinna inverse problem is formulated and solved for tropical meromorphic functions and tropical hypersurfaces.

A generalized exponential matrix based on the construction of kernel operators for generalized summability is defined and analyzing its main properties, generalizing the classical exponential matrix and fractional exponential matrix. This object serves as a practical tool to express the solutions of linear systems of moment differential equations in a compact manner, in the spirit of the classical exponential matrix.

An endomorphism $f:\mathbb{P}^k\to\mathbb{P}^k$ of degree $d\geq2$ is said to be postcritically finite (or PCF) if its critical set $\mathrm{Crit}(f)$ is preperiodic, i.e. if there are integers $m>n\geq0$ such that $f^m(\mathrm{Crit}(f))\subseteq f^n(\mathrm{Crit}(f))$. When $k\geq2$, it was conjectured by Ingram, Ramadas and Silverman that, in the space $\mathrm{End}_d^k$ of all endomorphisms of degree $d$ of $\mathbb{P}^k$, such endomorphisms are not Zariski dense. We prove this conjecture. Further, in the space $\mathrm{Poly}_d^2$ of all regular polynomial endomorphisms of degree $d\geq2$ of the affine plane $\mathbb{A}^2$, we construct a dense and Zariski open subset where we have a uniform bound on the number of preperiodic points lying in the critical set. The proofs are a combination of the theory of heights in arithmetic dynamics and methods from real dynamics to produce open subsets with maximal bifurcation., 76 pages, 2 figures. Comments are welcome!

Under a mild technical assumption, we prove a necessary and sufficient condition for a totally real compacdt set in $\mathbb{C}^n$ to be rationally convex. This generalizes a classical result of Duval-Sibony

We discuss the geometry of the unit ball -- specifically, the structure of its extreme points (if any) -- in subspaces of $L^1$ and $L^\infty$ on the circle that are formed by functions with prescribed spectral gaps. A similar issue is considered for kernels of Toeplitz operators in $H^\infty$., Comment: 10 pages

We investigate compact complex manifolds endowed with SKT or balanced metrics. In each case we define a new functional whose critical points are proved to be precisely the K\"ahler metrics, if any, on the manifold. As general manifolds of either type need not admit K\"ahler metrics, this provides an approach to new obstructions to K\"ahlerianity within these two families of metrics., Comment: 35 pages; to appear in J. Math. Pures Appl. (2023), https://doi.org/10.1016/j.matpur.2023.05.008

We consider the explicit relation between two resolvent matrices related to the truncated Hausdorff matrix moment problem (THMM) in the case of an even and odd number of moments. This relation is described with the help of four families of orthogonal matrix polynomials on the finite interval $[a,b]$ and their associated second kind polynomials.

This article introduces $L^p$ versions of the support function of a convex body $K$ and associates to these canonical $L^p$-polar bodies $K^{\circ, p}$ and Mahler volumes $\mathcal{M}_p(K)$. Classical polarity is then seen as $L^\infty$-polarity. This one-parameter generalization of polarity leads to a generalization of the Mahler conjectures, with a subtle advantage over the original conjecture: conjectural uniqueness of extremizers for each $p\in(0,\infty)$. We settle the upper bound by demonstrating the existence and uniqueness of an $L^p$-Santal\'o point and an $L^p$-Santal\'o inequality for symmetric convex bodies. The proof uses Ball's Brunn--Minkowski inequality for harmonic means, the classical Brunn--Minkowski inequality, symmetrization, and a systematic study of the $\mathcal{M}_p$ functionals. Using our results on the $L^p$-Santal\'o point and a new observation motivated by complex geometry, we show how Bourgain's slicing conjecture can be reduced to lower bounds on the $L^p$-Mahler volume coupled with a certain conjectural convexity property of the logarithm of the Monge--Amp\`ere measure of the $L^p$-support function. We derive a suboptimal version of this convexity using Kobayashi's theorem on the Ricci curvature of Bergman metrics to illustrate this approach to slicing. Finally, we explain how Nazarov's complex analytic approach to the classical Mahler conjecture is instead precisely an approach to the $L^1$-Mahler conjecture.

Let $\Omega$ be a region in the complex plane $\mathbb C$ and let $\{\Phi_t \}_{t\ge 0}$ be a continuous semigroup of functions on $\Omega$; that is, $\Phi_t\colon \Omega\to\Omega$ is holomorphic for every $t\ge 0$, $\Phi_0(z)=z$, for every $z\in\Omega$, $\Phi_t\circ\Phi_s=\Phi_{s+t}$, for every $s$, $t\ge 0$, and \begin{equation*}\label{eso} \Phi_t(z)\to z\,,\quad\hbox{ as $t$ goes to $0^+$,} \end{equation*} uniformly on compact subsets of $\Omega$. Despite this definition only requires the uniform convergence on compact subsets, P. Gumenyuk proved in 2014 that, when $\Omega$ is the unit disc, the convergence is uniform on the whole $\mathbb D$. When $\Omega$ is a half-plane, it is not difficult to show that the result is no longer true. In this paper, we enhance Gumenyuk's result by proving that for every continuous semigroup $\{\Phi_t \}_{t\ge 0}$ on $\mathbb D$ we have $$ \sup_{z\in\mathbb D} |\Phi_t(z)-z|= O(\sqrt t), \quad t\to 0^+. $$ In addition, we provide an example showing that $O(\sqrt t)$ is the best possible rate of uniform convergence valid for all semigroups on $\mathbb D$. When $\Omega$ is a half-plane we prove that there is uniform convergence to the identity under certain boundedness conditions on the infinitesimal generator of the semigroup. These boundedness conditions are fulfilled when the semigroup $\{\Phi_t \}_{t\ge 0}$ is included in the Gordon-Hedenmalm class (the one which produces bounded composition operators on Hardy spaces of Dirichlet series). An important ingredient in the proofs of these results is the use of harmonic measures, which we have done through a classic result of M. Lavrentiev., Comment: 22 pages, 1 figure

Let $F=(\phi, \psi):\mathbb{D}^2\to\mathbb{D}^2$ denote a holomorphic self-map of the bidisk without interior fixed points. It is well-known that, unlike the case with self-maps of the disk, the sequence of iterates $$\{F^n:=F\circ F\circ \cdots \circ F\}$$ needn't converge. The cluster set of $\{F^n\}$ was described in a classical 1954 paper of Herv\'{e}. Motivated by Herv\'{e}'s work and the Hilbert space perspective of Agler, McCarthy and Young on boundary regularity, we propose a new approach to boundary points of Denjoy-Wolff type for the coordinate maps $\phi, \psi.$ We establish several equivalent descriptions of our Denjoy-Wolff points, some of which only involve checking specific directional derivatives and are particularly convenient for applications. Using these tools, we are able to refine Herv\'{e}'s theorem and show that, under the extra assumption of $\phi$ and $\psi$ possessing Denjoy-Wolff points with certain regularity properties, one can draw much stronger conclusions regarding the behavior of $\{F^n\}.$

In this paper we study uniform quasiconformal groups of Carnot-by-Carnot groups. We show that they can be conjugated into conformal groups provided the induced action on the space of distinct pairs is cocompact. Following the approach of Eskin-Fisher-Whyte these results have applications to quasi-isometric rigidity of certain solvable groups., 60 pages

We show that the measure of maximal entropy of every complex H\'enon map is exponentially mixing of all orders for H\''older observables. As a consequence, the Central Limit Theorem holds for all H\''older observables.

The celebrated Ohsawa-Takegoshi extension theorem for $L^2$ holomorphic functions on bounded pseudoconvex domains in $\mathbb C^n$ is an important and powerful tool in several complex variables and complex geometry. Ohsawa conjectured in 1995 that the same theorem holds for more general bounded complete K\"ahler domains in $\mathbb C^n$. Recently, Chen-Wu-Wang confirmed this conjecture in a special case. In this paper we extend their result to the case of holomorphic sections of twisted canonical bundles over relatively compact complete K\"{a}hler domains in Stein manifolds. As an application we prove a Hartogs type extension theorem for plurisubharmonic functions across a compact complete pluripolar set, which is complementary to a classical theorem of Shiffman and can be thought of as an analogue of the Skoda-El Mir extension theorem for plurisubharmonic functions., Comment: 18 pages

In this Thesis we deal with problems regarding boundary behavior of analytic functions and approximation theory. We will begin by characterizing the set in which Blaschke products fail to have radial limits but have unrestricted limits on its complement. We will then proceed and solve several cases of an open problem posed in \cite{Da}. The goal of the problem is to unify two known theorems to create a stronger theorem; in particular we want to find necessary and sufficient conditions on sets $E_1\subset E_2$ of the unit circle such that there exists a bounded analytic function that fails to have radial limits exactly on $E_1$, but has unrestricted limits exactly on the complement of $E_2$. One of the several cases extends the main theorem proven by Peter Colwell found in [10] regarding boundary behavior of Blaschke products. Additionally, we will provide a shorter proof for the necessity part of the main result in [10] which relies on a classical result proven by R. Baire. The sufficiency part of that result will then be used to shorten another proof by A.J Lohwater and G. Piranian found in [23]. Lastly, we will provide an extension of a well known theorem of Arakeljan about approximating continuous functions which are analytic in the interior of a closed set, by functions analytic in a larger domain., PhD thesis

A Hopf manifold is a quotient of $C^n\backslash 0$ by the cyclic group generated by a holomorphic contraction. Hopf manifolds are diffeomorphic to $S^1\times S^{2n-1}$ and hence do not admit Kahler metrics. It is known that Hopf manifolds defined by linear contractions (called linear Hopf manifolds) have locally conformally Kahler (LCK) metrics. In this paper we prove that the Hopf manifolds defined by non-linear holomorphic contractions admit holomorphic embeddings into linear Hopf manifolds, and, moreover they admit LCK metrics., 11 pages, Latex (no change in the article, but the title in the submission was wrong)

We prove an asymptotic formula for the partition function of a 2d Coulomb gas at inverse temperature $\beta>0$ confined to lie on a Jordan curve. This also gives a central limit theorem for a linear statistic of the particles in the gas. We obtain different expressions for the asymptotic mean and variance which involve either the exterior conformal mapping of the curve or the Grunsky operator., Comment: 22 pages

In their previous work, the authors proved the Berger-Coburn phenomenon for compact and Schatten $S_p$ class Hankel operators $H_f$ on generalized Fock spaces when $1

Let ( X , ω ) (X,\omega ) be a compact hermitian manifold of dimension n n . We study the asymptotic behavior of Monge-Ampère volumes ∫ X ( ω + d d c φ ) n \int _X (\omega +dd^c \varphi )^n , when ω + d d c φ \omega +dd^c \varphi varies in the set of hermitian forms that are d d c dd^c -cohomologous to ω \omega . We show that these Monge-Ampère volumes are uniformly bounded if ω \omega is “strongly pluripositive”, and that they are uniformly positive if ω \omega is “strongly plurinegative”. This motivates the study of the existence of such plurisigned hermitian metrics. We analyze several classes of examples (complex parallelisable manifolds, twistor spaces, Vaisman manifolds) admitting such metrics, showing that they cannot coexist. We take a close look at 6 6 -dimensional nilmanifolds which admit a left-invariant complex structure, showing that each of them admit a plurisigned hermitian metric, while only few of them admit a pluriclosed metric. We also study 6 6 -dimensional solvmanifolds with trivial canonical bundle.

We investigate certain classes of $M_z$-invariant subspaces for a wide range of growth spaces on the unit disc $\mathbb{D}$ determined by a majorant $w$, which include the classical Korenblum growth spaces. Our main result generalizes the classical Korenblum-Roberts Theorem on the description of $M_z$-invariant subspaces generated by bounded analytic functions, in terms of the corresponding Nevanlinna measure. It turns out that sets of finite $w$-entropy, which are boundary zero sets for analytic functions in $\mathbb{D}$ having modulus of continuity not exceeding $w$ on $\overline{\mathbb{D}}$, play the decisive role in this setting. This further enables us to establish an intimate link between $M_z$-invariant subspace generated by inner functions $\Theta$ and the containment of the above mentioned analytic function spaces in the corresponding model spaces $K_\Theta$., Comment: 29 pages

In this paper, we characterize the stability region for trinomials of the form $f(\zeta):=a\zeta ^n + b\zeta ^m +c$, $\zeta\in \mathbb{C}$, where $a$, $b$ and $c$ are non-zero complex numbers and $n,m\in \mathbb{N}$ with $n>m$. More precisely, we provide necessary and sufficient conditions on the coefficients $a$, $b$ and $c$ in order that all the roots of the trinomial $f$ belongs to the open unit disc in the complex plane. The proof is based on Bohl's Theorem introduced in 1908., Comment: 20 pages and 1 figure

In this note, we discuss the following problem: Given a smoothly bounded strongly pseudoconvex domain $D$ in $\mathbb{C}^n$, can we guarantee the existence of geodesics for the Kobayashi--Fuks metric which ``spiral around" in the interior of $D$? We find an affirmative answer to the above question for $n=1$ when $D$ is not simply connected., Comment: 12 pages, Introduction modified

The modification of the coefficients of formal power series is analyzed in order that such variation preserves q-Gevrey asymptotic properties, in particular q-Gevrey asymptotic expansions. A characterization of such sequences is determined, providing a handy tool in practice. The sequence of q-factorials is proved to preserve q-Gevrey asymptotic expansions.

It was shown in arXiv:2303.02036 that the affine cones over flag manifolds and rational smooth projective surfaces are elliptic in the sense of Gromov. The latter remains true after successive blowups of points on these varieties. In the present note we extend this to smooth projective spherical varieties (in particular, toric varieties) successively blown up along smooth subvarieties. The same also holds, more generally, for uniformly rational projective varieties, in particular, for projective varieties covered by affine spaces., 16 pages; Corollary 1.7, Remarks 1.8 and some references added

This work presents a family of fiber bundles where the total spaces are associated with holomorphic functions on several complex variables and the basis spaces extend the notion of quaternionic slice regular functions of several quaternionic variables. This paper also shows how the fiber bundle theory justifies the domain these slice regular function in several variables.

In this paper we introduced the class SG* of analytic functions which is related with starlike functions and generating functionof Gregory coefficients. By using bounds on some coefficient functionals for the family of functions with positive real part, we obtain several sharp coefficient bounds on the first six coeffcients and also further sharp bounds on the corresponding Hankel determinants for functions in the class SG*. Additionally, the sharp bounds for logarithmic and inverse coefficients of functions belonging to the considered class SG* were estimated. Mathematics Subject Classification (2010). Priminary 30C45; Secondary 30C50, 30C80.

We establish basic properties of the heat flow on entire holomorphic functions that have order at most 2. We then look specifically at the action of the heat flow on the Gaussian analytic function (GAF). We show that applying the heat flow to a GAF and then rescaling and multiplying by an exponential of a quadratic function gives another GAF. It follows that the zeros of the GAF are invariant in distribution under the heat flow, up to a simple rescaling. We then show that the zeros of the GAF evolve under the heat flow approximately along straight lines, with an error whose distribution is independent of the starting point. Finally, we connect the heat flow on the GAF to the metaplectic representation of the double cover of the group $SL(2;\mathbb{R}).$, 46 pages, 2 figures

We generalize a fundamental theorem in higher dimensional value distribution theory about entire curves in subvarieties $X$ of semi-abelian varieties to the situation of the sequences of holomorphic maps from the unit disc into $X$. This generalization implies, among other things, that subvarieties of log general type in semi-abelian varieties are pseudo-Kobayashi hyperbolic. As another application, we improve a classical theorem due to Cartan in 1920's about the system of nowhere vanishing holomorphic functions on the unit disc satisfying Borel's identity., 109 pages

We establish two-point distortion theorems for sense-preserving planar harmonic mappings $f=h+\overline{g}$ which satisfies the univalence criteria in the unit disc such that, Becker's and Nehari`s harmonic version. In addition, we find the sharp two-point distortion theorem when $h$ is a convex function, and normalized mappings such that $h(\D)$ is a $c$-linearly connected domain. To do this, we use the order of this family.

We study two variations of the classical one-delta problem for entire functions of exponential type, known also as the Carath\'eodory--Fej\'er--Tur\'an problem. The first variation imposes the additional requirement that the function is radially decreasing while the second one is a generalization which involves derivatives of the entire function. Various interesting inequalities, inspired by results due to Duffin and Schaeffer, Landau, and Hardy and Littlewood, are also established., Comment: 14 pages, 4 figures

We prove several new formulas for the visual angle metric of the unit disk in terms of the hyperbolic metric and apply these to prove a sharp Schwarz lemma for the visual angle metric under quasiconformal mapping., 14 pages, 9 Figures

In this work, we provide a complete characterization of the boundedness of two classes of multiparameter Forelli-Rudin type operators from one mixed-norm Lebesgue space $L^{\vec p}$ to another space $L^{\vec q}$, when $1\leq \vec{p}\leq \vec q, 42 pages

This paper considers composition operators on Zen spaces (a class of weighted Bergman spaces of the right half-plane related to weighted function spaces on the positive half-line by means of the Laplace transform). Generalizations are given to work of Kucik on norms and essential norms, to work of Schroderus on (essential) spectra, and to work by Arvanitidis and the authors on semigroups of composition operators. The results are illustrated by consideration of the Hardy--Bergman space; that is, the intersection of the Hardy and Bergman Hilbert spaces on the half-plane., 14 pages

Arakeljan's Theorem provides conditions on a relatively closed subset $F$ of a domain $G\subset\mathbb{C}$, such that any continuous function $f:F\rightarrow\mathbb{C}$ that is analytic in $F^\circ$, can be approximated by analytic functions defined on $G$. In this paper we will extend Arakeljan's theorem by adding the extra requirement that the analytic functions that approximate $f$ may also be chosen to be bounded on a closed set $C\subset G.$ In \cite{RU} the same problem has been considered but for the specific case that $G=\mathbb{C}$. In this paper we will extend the result in \cite{RU} and show that is true for an arbitrary $G$, provided that $F$ and $C$ satisfy a certain condition in $G$. Additionally, we will show that the result holds always true when $G$ is simply connected.

We discuss the solution of the Neumann problem associated with the CR Yamabe operator on a subset $\Omega$ of the CR manifold $\mathbb{S}^3$ bounded by the Clifford torus $\Sigma$. We also discuss the Yamabe-type problem of finding a contact form on $\Omega$ which has zero Tanaka--Webster scalar curvature and for which $\Sigma$ has constant $p$-mean curvature., Comment: 36 pages

In this paper, we combine tools in pluripotential theory and commutative algebra to study singularity invariants of plurisubharmonic functions. We obtain some relationships between singularity invariants of plurisubharmonic functions and holomorphic functions. These results lead a sharp lower bound for the log canonical threshold of a plurisubharmonic function. It simultaneously improves the main result in Demailly and Pham (Acta. Math 212: 1-9, 2014), the classical result due to Skoda (Bull. Soc. Math. France 100: 353-408, 1972), as well as the lower estimate in Fernex, Ein and Mustata (Math. Res. Lett: 10 219-236, 2003) which has received crucial applications to birational geometry in recent years., 18 pages

The aim of this paper is to extend two results from the Paley--Wiener setting to more generalmodel spaces. The first one is an analogue of the oversampling Shannon sampling formula. The second one is a version of Donoho--Logan's Large Sieve Theorem which is a quantitative estimate of the embedding of the Paley--Wiener space into an $L^2(\R,\mu)$ space.

In this article, we consider the minimal $L^2$ integrals for the Hardy spaces and the Bergman spaces, and we present some relations between them, which can be regarded as the solutions of the finite points versions of Saitoh's conjecture for conjugate Hardy kernels. As applications, we give optimal $L^2$ extension theorems for the Hardy spaces, and characterizations for the holding of the equality in the optimal $L^2$ extension theorems., 50 pages, all comments are welcome. arXiv admin note: substantial text overlap with arXiv:2210.14579

We propose and investigate two types, the latter with two variants, of notions of partial hyperbolicity accounting for several classes of compact complex manifolds behaving hyperbolically in certain directions, defined by a vector subbundle of the holomorphic tangent bundle, but not necessarily in the other directions. We study several classes of examples, prove implications among these notions, give a sufficient criterion for the existence of an Ahlfors current and a sufficient criterion for partial hyperbolicity in terms of the signs of two curvature-like objects introduced recently by the second-named author., 33 pages

We introduce the notion of a regular integrable connection on a smooth log scheme over $\mathbf{C}$ and construct an equivalence between the category of such connections and the category of integrable connections on its analytification, compatible with de Rham cohomology. This extends the work of Deligne (when the log structure is trivial), and combined with the work of Ogus yields a topological description of the category of regular connections in terms of certain constructible sheaves on the Kato--Nakayama space. The key ingredients are the notion of a canonical extension in this context and the existence of good compactifications of log schemes obtained recently by W{\l}odarczyk., Comment: 36 pages, comments welcome!

We present complete classifications of automorphisms of two closed subalgebras of the bounded analytic functions on the open unit disc $\mathbb{D}$, namely, the subalgebra of functions vanishing at the origin, and the subalgebra of functions whose first derivative vanishes at the origin. The later subalgebra is known as the Neil algebra. We also characterize generalized tri-circular projections on $H^{p}(\mathbb{D})$ and $H^{p}(\mathbb{D}^2)$, $1\leq p \leq \infty$, $p\neq 2$., 20 pages

For a positive finite Borel measure $\mu$ compactly supported in the complex plane, the space $\mathcal{P}^2(\mu)$ is the closure of the analytic polynomials in the Lebesgue space $L^2(\mu)$. According to Thomson's famous result, any space $\mathcal{P}^2(\mu)$ decomposes as an orthogonal sum of pieces which are essentially analytic, and a residual $L^2$-space. We study the structure of this decomposition for a class of Borel measures $\mu$ supported on the closed unit disk for which the part $\mu_\mathbb{D}$, living in the open disk $\mathbb{D}$, is radial and decreases at least exponentially fast near the boundary of the disk. For the considered class of measures, we give a precise form of the Thomson decompsition. In particular, we confirm a conjecture of Kriete and MacCluer from 1990, which gives an analog to Szeg\"o's classical theorem.